Remove some horrible munging of origins for Coercible

I just didn't think it was buying enough for all the cruft it caused.
We can put some back if people start complaining about poor error
messages. I forget quite how I tripped over this but I got sucked in.

* Lots of tidying up in TcErrors

* Rename pprArisingAt to pprCtLoc, by analogy with pprCtOrigin

* Remove CoercibleOrigin data constructor from CtOrigin

* Make relevantBindings return a Ct with a zonked
  and tidied CtOrigin

* Add to TcRnTypes
      ctOrigin   :: Ct -> CtOrigin
      ctEvOrigin :: CtEvidence -> CtOrigin
      setCtLoc   :: Ct -> CtLoc -> Ct

6 files changed, 59 insertions, 59 deletions

diff --git a/testsuite/tests/ghci/scripts/Defer02.stderr b/testsuite/tests/ghci/scripts/Defer02.stderr
index 69e098a883..a3a3e9d061 100644
--- a/testsuite/tests/ghci/scripts/Defer02.stderr
+++ b/testsuite/tests/ghci/scripts/Defer02.stderr
@@ -1,5 +1,5 @@
 
-../../typecheck/should_run/Defer01.hs:11:40: Warning:
+../../typecheck/should_run/Defer01.hs:11:40: warning:
     Couldn't match type ‘Char’ with ‘[Char]’
     Expected type: String
       Actual type: Char
@@ -7,17 +7,17 @@
     In the second argument of ‘(>>)’, namely ‘putStr ','’
     In the expression: putStr "Hello World" >> putStr ','
 
-../../typecheck/should_run/Defer01.hs:14:5: Warning:
+../../typecheck/should_run/Defer01.hs:14:5: warning:
     Couldn't match expected type ‘Int’ with actual type ‘Char’
     In the expression: 'p'
     In an equation for ‘a’: a = 'p'
 
-../../typecheck/should_run/Defer01.hs:18:9: Warning:
+../../typecheck/should_run/Defer01.hs:18:9: warning:
     No instance for (Eq B) arising from a use of ‘==’
     In the expression: x == x
     In an equation for ‘b’: b x = x == x
 
-../../typecheck/should_run/Defer01.hs:25:4: Warning:
+../../typecheck/should_run/Defer01.hs:25:4: warning:
     Couldn't match type ‘Int’ with ‘Bool’
     Inaccessible code in
       a pattern with constructor: C2 :: Bool -> C Bool,
@@ -25,14 +25,14 @@
     In the pattern: C2 x
     In an equation for ‘c’: c (C2 x) = True
 
-../../typecheck/should_run/Defer01.hs:28:5: Warning:
+../../typecheck/should_run/Defer01.hs:28:5: warning:
     No instance for (Num (a -> a))
       (maybe you haven't applied a function to enough arguments?)
       arising from the literal ‘1’
     In the expression: 1
     In an equation for ‘d’: d = 1
 
-../../typecheck/should_run/Defer01.hs:31:5: Warning:
+../../typecheck/should_run/Defer01.hs:31:5: warning:
     Couldn't match expected type ‘Char -> t’ with actual type ‘Char’
     Relevant bindings include
       f :: t (bound at ../../typecheck/should_run/Defer01.hs:31:1)
@@ -41,11 +41,11 @@
     In the expression: e 'q'
     In an equation for ‘f’: f = e 'q'
 
-../../typecheck/should_run/Defer01.hs:34:8: Warning:
+../../typecheck/should_run/Defer01.hs:34:8: warning:
     Couldn't match expected type ‘Char’ with actual type ‘a’
-      ‘a’ is a rigid type variable bound by
-          the type signature for: h :: a -> (Char, Char)
-          at ../../typecheck/should_run/Defer01.hs:33:6
+    ‘a’ is a rigid type variable bound by
+        the type signature for: h :: a -> (Char, Char)
+        at ../../typecheck/should_run/Defer01.hs:33:6
     Relevant bindings include
       x :: a (bound at ../../typecheck/should_run/Defer01.hs:34:3)
       h :: a -> (Char, Char)
@@ -53,7 +53,7 @@
     In the expression: x
     In the expression: (x, 'c')
 
-../../typecheck/should_run/Defer01.hs:39:17: Warning:
+../../typecheck/should_run/Defer01.hs:39:17: warning:
     Couldn't match expected type ‘Bool’ with actual type ‘T a’
     Relevant bindings include
       a :: a (bound at ../../typecheck/should_run/Defer01.hs:39:3)
@@ -61,12 +61,12 @@
     In the first argument of ‘not’, namely ‘(K a)’
     In the expression: (not (K a))
 
-../../typecheck/should_run/Defer01.hs:43:5: Warning:
+../../typecheck/should_run/Defer01.hs:43:5: warning:
     No instance for (MyClass a1) arising from a use of ‘myOp’
     In the expression: myOp 23
     In an equation for ‘j’: j = myOp 23
 
-../../typecheck/should_run/Defer01.hs:43:10: Warning:
+../../typecheck/should_run/Defer01.hs:43:10: warning:
     No instance for (Num a1) arising from the literal ‘23’
     The type variable ‘a1’ is ambiguous
     Note: there are several potential instances:
@@ -78,7 +78,7 @@
     In the expression: myOp 23
     In an equation for ‘j’: j = myOp 23
 
-../../typecheck/should_run/Defer01.hs:45:6: Warning:
+../../typecheck/should_run/Defer01.hs:45:6: warning:
     Couldn't match type ‘Int’ with ‘Bool’
     Inaccessible code in
       the type signature for: k :: (Int ~ Bool) => Int -> Bool
@@ -87,30 +87,30 @@
     To defer the ambiguity check to use sites, enable AllowAmbiguousTypes
     In the type signature for ‘k’: k :: (Int ~ Bool) => Int -> Bool
 
-../../typecheck/should_run/Defer01.hs:45:6: Warning:
+../../typecheck/should_run/Defer01.hs:45:6: warning:
     Couldn't match expected type ‘Bool’ with actual type ‘Int’
     In the ambiguity check for the type signature for ‘k’:
       k :: (Int ~ Bool) => Int -> Bool
     To defer the ambiguity check to use sites, enable AllowAmbiguousTypes
     In the type signature for ‘k’: k :: (Int ~ Bool) => Int -> Bool
 
-../../typecheck/should_run/Defer01.hs:45:6: Warning:
+../../typecheck/should_run/Defer01.hs:45:6: warning:
     Couldn't match type ‘Int’ with ‘Bool’
     Inaccessible code in
       the type signature for: k :: (Int ~ Bool) => Int -> Bool
 
-../../typecheck/should_run/Defer01.hs:46:7: Warning:
+../../typecheck/should_run/Defer01.hs:46:7: warning:
     Couldn't match expected type ‘Bool’ with actual type ‘Int’
     In the expression: x
     In an equation for ‘k’: k x = x
 
-../../typecheck/should_run/Defer01.hs:49:5: Warning:
+../../typecheck/should_run/Defer01.hs:49:5: warning:
     Couldn't match expected type ‘IO a0’
                 with actual type ‘Char -> IO ()’
     Probable cause: ‘putChar’ is applied to too few arguments
     In the first argument of ‘(>>)’, namely ‘putChar’
     In the expression: putChar >> putChar 'p'
-*** Exception: ../../typecheck/should_run/Defer01.hs:11:40:
+*** Exception: ../../typecheck/should_run/Defer01.hs:11:40: error:
     Couldn't match type ‘Char’ with ‘[Char]’
     Expected type: String
       Actual type: Char
@@ -118,31 +118,31 @@
     In the second argument of ‘(>>)’, namely ‘putStr ','’
     In the expression: putStr "Hello World" >> putStr ','
 (deferred type error)
-*** Exception: ../../typecheck/should_run/Defer01.hs:14:5:
+*** Exception: ../../typecheck/should_run/Defer01.hs:14:5: error:
     Couldn't match expected type ‘Int’ with actual type ‘Char’
     In the expression: 'p'
     In an equation for ‘a’: a = 'p'
 (deferred type error)
-*** Exception: ../../typecheck/should_run/Defer01.hs:18:9:
+*** Exception: ../../typecheck/should_run/Defer01.hs:18:9: error:
     No instance for (Eq B) arising from a use of ‘==’
     In the expression: x == x
     In an equation for ‘b’: b x = x == x
 (deferred type error)
 
-<interactive>:8:11:
+<interactive>:8:11: error:
     Couldn't match type ‘Bool’ with ‘Int’
     Expected type: C Int
       Actual type: C Bool
     In the first argument of ‘c’, namely ‘(C2 True)’
     In the first argument of ‘print’, namely ‘(c (C2 True))’
-*** Exception: ../../typecheck/should_run/Defer01.hs:28:5:
+*** Exception: ../../typecheck/should_run/Defer01.hs:28:5: error:
     No instance for (Num (a -> a))
       (maybe you haven't applied a function to enough arguments?)
       arising from the literal ‘1’
     In the expression: 1
     In an equation for ‘d’: d = 1
 (deferred type error)
-*** Exception: ../../typecheck/should_run/Defer01.hs:31:5:
+*** Exception: ../../typecheck/should_run/Defer01.hs:31:5: error:
     Couldn't match expected type ‘Char -> t’ with actual type ‘Char’
     Relevant bindings include
       f :: t (bound at ../../typecheck/should_run/Defer01.hs:31:1)
@@ -151,11 +151,11 @@
     In the expression: e 'q'
     In an equation for ‘f’: f = e 'q'
 (deferred type error)
-*** Exception: ../../typecheck/should_run/Defer01.hs:34:8:
+*** Exception: ../../typecheck/should_run/Defer01.hs:34:8: error:
     Couldn't match expected type ‘Char’ with actual type ‘a’
-      ‘a’ is a rigid type variable bound by
-          the type signature for: h :: a -> (Char, Char)
-          at ../../typecheck/should_run/Defer01.hs:33:6
+    ‘a’ is a rigid type variable bound by
+        the type signature for: h :: a -> (Char, Char)
+        at ../../typecheck/should_run/Defer01.hs:33:6
     Relevant bindings include
       x :: a (bound at ../../typecheck/should_run/Defer01.hs:34:3)
       h :: a -> (Char, Char)
@@ -163,7 +163,7 @@
     In the expression: x
     In the expression: (x, 'c')
 (deferred type error)
-*** Exception: ../../typecheck/should_run/Defer01.hs:39:17:
+*** Exception: ../../typecheck/should_run/Defer01.hs:39:17: error:
     Couldn't match expected type ‘Bool’ with actual type ‘T a’
     Relevant bindings include
       a :: a (bound at ../../typecheck/should_run/Defer01.hs:39:3)
@@ -171,18 +171,18 @@
     In the first argument of ‘not’, namely ‘(K a)’
     In the expression: (not (K a))
 (deferred type error)
-*** Exception: ../../typecheck/should_run/Defer01.hs:43:5:
+*** Exception: ../../typecheck/should_run/Defer01.hs:43:5: error:
     No instance for (MyClass a1) arising from a use of ‘myOp’
     In the expression: myOp 23
     In an equation for ‘j’: j = myOp 23
 (deferred type error)
 
-<interactive>:14:8:
+<interactive>:14:8: error:
     Couldn't match expected type ‘Bool’ with actual type ‘Int’
     In the first argument of ‘print’, namely ‘(k 2)’
     In the expression: print (k 2)
     In an equation for ‘it’: it = print (k 2)
-*** Exception: ../../typecheck/should_run/Defer01.hs:49:5:
+*** Exception: ../../typecheck/should_run/Defer01.hs:49:5: error:
     Couldn't match expected type ‘IO a0’
                 with actual type ‘Char -> IO ()’
     Probable cause: ‘putChar’ is applied to too few arguments
diff --git a/testsuite/tests/ghci/scripts/T8649.stderr b/testsuite/tests/ghci/scripts/T8649.stderr
index 1fe41defdc..257b112112 100644
--- a/testsuite/tests/ghci/scripts/T8649.stderr
+++ b/testsuite/tests/ghci/scripts/T8649.stderr
@@ -1,8 +1,8 @@
 
-<interactive>:5:4:
+<interactive>:5:4: error:
     Couldn't match expected type ‘Ghci1.X’
                 with actual type ‘X’
-    NB: ‘Ghci1.X’ is defined at <interactive>:2:1-14
-        ‘X’ is defined at <interactive>:4:1-25
+    NB: ‘X’ is defined at <interactive>:4:1-25
+        ‘Ghci1.X’ is defined at <interactive>:2:1-14
     In the first argument of ‘f’, namely ‘(Y 3)’
     In the expression: f (Y 3)
diff --git a/testsuite/tests/ghci/scripts/ghci050.stderr b/testsuite/tests/ghci/scripts/ghci050.stderr
index 4c8de9da4e..d1df9b8379 100644
--- a/testsuite/tests/ghci/scripts/ghci050.stderr
+++ b/testsuite/tests/ghci/scripts/ghci050.stderr
@@ -1,9 +1,9 @@
 
-<interactive>:6:49:
+<interactive>:6:49: error:
     Couldn't match expected type ‘ListableElem (a, a)’
                 with actual type ‘a’
-      ‘a’ is a rigid type variable bound by
-          the instance declaration at <interactive>:6:10
+    ‘a’ is a rigid type variable bound by
+        the instance declaration at <interactive>:6:10
     Relevant bindings include
       b :: a (bound at <interactive>:6:43)
       a :: a (bound at <interactive>:6:41)
diff --git a/testsuite/tests/ghci/scripts/ghci051.stderr b/testsuite/tests/ghci/scripts/ghci051.stderr
index 3b6ad44d93..2a528e847a 100644
--- a/testsuite/tests/ghci/scripts/ghci051.stderr
+++ b/testsuite/tests/ghci/scripts/ghci051.stderr
@@ -1,9 +1,9 @@
 
-<interactive>:7:9:
+<interactive>:7:9: error:
     Couldn't match type ‘T’
                    with ‘Ghci1.T’
-    NB: ‘T’ is defined at <interactive>:6:1-16
-        ‘Ghci1.T’ is defined at <interactive>:3:1-14
+    NB: ‘Ghci1.T’ is defined at <interactive>:3:1-14
+        ‘T’ is defined at <interactive>:6:1-16
     Expected type: T'
       Actual type: T
     In the expression: C :: T'
diff --git a/testsuite/tests/ghci/scripts/ghci052.stderr b/testsuite/tests/ghci/scripts/ghci052.stderr
index b2b0c7613b..ce221887d6 100644
--- a/testsuite/tests/ghci/scripts/ghci052.stderr
+++ b/testsuite/tests/ghci/scripts/ghci052.stderr
@@ -1,32 +1,32 @@
 
-<interactive>:9:4:
+<interactive>:9:4: error:
     Couldn't match expected type ‘Ghci1.Planet’
                 with actual type ‘Planet’
-    NB: ‘Ghci1.Planet’ is defined at <interactive>:5:1-37
-        ‘Planet’ is defined at <interactive>:8:1-36
+    NB: ‘Planet’ is defined at <interactive>:8:1-36
+        ‘Ghci1.Planet’ is defined at <interactive>:5:1-37
     In the first argument of ‘pn’, namely ‘Mercury’
     In the expression: pn Mercury
 
-<interactive>:10:4:
+<interactive>:10:4: error:
     Couldn't match expected type ‘Ghci1.Planet’
                 with actual type ‘Planet’
-    NB: ‘Ghci1.Planet’ is defined at <interactive>:5:1-37
-        ‘Planet’ is defined at <interactive>:8:1-36
+    NB: ‘Planet’ is defined at <interactive>:8:1-36
+        ‘Ghci1.Planet’ is defined at <interactive>:5:1-37
     In the first argument of ‘pn’, namely ‘Venus’
     In the expression: pn Venus
 
-<interactive>:11:4:
+<interactive>:11:4: error:
     Couldn't match expected type ‘Ghci1.Planet’
                 with actual type ‘Planet’
-    NB: ‘Ghci1.Planet’ is defined at <interactive>:5:1-37
-        ‘Planet’ is defined at <interactive>:8:1-36
+    NB: ‘Planet’ is defined at <interactive>:8:1-36
+        ‘Ghci1.Planet’ is defined at <interactive>:5:1-37
     In the first argument of ‘pn’, namely ‘Mars’
     In the expression: pn Mars
 
-<interactive>:13:44:
+<interactive>:13:44: error:
     Couldn't match expected type ‘Planet’
                 with actual type ‘Ghci1.Planet’
-    NB: ‘Planet’ is defined at <interactive>:8:1-36
-        ‘Ghci1.Planet’ is defined at <interactive>:5:1-37
+    NB: ‘Ghci1.Planet’ is defined at <interactive>:5:1-37
+        ‘Planet’ is defined at <interactive>:8:1-36
     In the pattern: Earth
     In an equation for ‘pn’: pn Earth = "E"
diff --git a/testsuite/tests/ghci/scripts/ghci053.stderr b/testsuite/tests/ghci/scripts/ghci053.stderr
index 2d91a51d21..fe6d6c9bef 100644
--- a/testsuite/tests/ghci/scripts/ghci053.stderr
+++ b/testsuite/tests/ghci/scripts/ghci053.stderr
@@ -1,16 +1,16 @@
 
-<interactive>:10:12:
+<interactive>:10:12: error:
     Couldn't match expected type ‘Ghci1.Planet’
                 with actual type ‘Planet’
-    NB: ‘Ghci1.Planet’ is defined at <interactive>:5:1-49
-        ‘Planet’ is defined at <interactive>:8:1-41
+    NB: ‘Planet’ is defined at <interactive>:8:1-41
+        ‘Ghci1.Planet’ is defined at <interactive>:5:1-49
     In the second argument of ‘(==)’, namely ‘Mercury’
     In the expression: mercury == Mercury
 
-<interactive>:12:10:
+<interactive>:12:10: error:
     Couldn't match expected type ‘Planet’
                 with actual type ‘Ghci1.Planet’
-    NB: ‘Planet’ is defined at <interactive>:8:1-41
-        ‘Ghci1.Planet’ is defined at <interactive>:5:1-49
+    NB: ‘Ghci1.Planet’ is defined at <interactive>:5:1-49
+        ‘Planet’ is defined at <interactive>:8:1-41
     In the second argument of ‘(==)’, namely ‘Earth’
     In the expression: Venus == Earth