SCC analysis for instances as well as types/classes

This big patch is in pursuit of Trac #11348.

It is largely the work of Alex Veith (thank you!), with some
follow-up simplification and refactoring from Simon PJ.

The main payload is described in RnSource
  Note [Dependency analysis of type, class, and instance decls]
which is pretty detailed.

* There is a new data type HsDecls.TyClGroup, for a strongly
  connected component of type/class/instance/role decls.

  The hs_instds field of HsGroup disappears, in consequence

  This forces some knock-on changes, including a minor
  haddock submodule update

Smaller, weakly-related things

* I found that both the renamer and typechecker were building an
  identical env for RoleAnnots, so I put common code for
  RoleAnnotEnv in RnEnv.

* I found that tcInstDecls1 had very clumsy error handling, so I
  put it together into TcInstDcls.doClsInstErrorChecks

12 files changed, 111 insertions, 84 deletions

diff --git a/testsuite/tests/deriving/should_fail/T9687.stderr b/testsuite/tests/deriving/should_fail/T9687.stderr
index 36425e48c8..a98f775bee 100644
--- a/testsuite/tests/deriving/should_fail/T9687.stderr
+++ b/testsuite/tests/deriving/should_fail/T9687.stderr
@@ -1,3 +1,5 @@
 
-T9687.hs:4:10: error:
-    Class ‘Typeable’ does not support user-specified instances
+T9687.hs:4:1: error:
+    • Class ‘Typeable’ does not support user-specified instances
+    • In the instance declaration for
+        ‘Typeable (a, b, c, d, e, f, g, h)’
diff --git a/testsuite/tests/driver/sigof02/Map.hsig b/testsuite/tests/driver/sigof02/Map.hsig
index cd094df17f..8e46f1d63f 100644
--- a/testsuite/tests/driver/sigof02/Map.hsig
+++ b/testsuite/tests/driver/sigof02/Map.hsig
@@ -14,7 +14,6 @@ infixl 9 !,\\
 type role Map nominal representational
 data Map k a
 
-instance Typeable Map
 instance Functor (Map k)
 instance Foldable (Map k)
 instance Traversable (Map k)
diff --git a/testsuite/tests/ghci/scripts/T4175.stdout b/testsuite/tests/ghci/scripts/T4175.stdout
index d319bd630e..f76feb6194 100644
--- a/testsuite/tests/ghci/scripts/T4175.stdout
+++ b/testsuite/tests/ghci/scripts/T4175.stdout
@@ -1,56 +1,56 @@
-type family A a b :: * 	-- Defined at T4175.hs:7:1

-type instance A (B a) b = () 	-- Defined at T4175.hs:10:15

-type instance A (Maybe a) a = a 	-- Defined at T4175.hs:9:15

-type instance A Int Int = () 	-- Defined at T4175.hs:8:15

-data family B a 	-- Defined at T4175.hs:12:1

-instance G B -- Defined at T4175.hs:34:10

-data instance B () = MkB 	-- Defined at T4175.hs:13:15

-type instance A (B a) b = () 	-- Defined at T4175.hs:10:15

-class C a where

-  type family D a b :: *

-  	-- Defined at T4175.hs:16:5

-type instance D () a = Bool 	-- Defined at T4175.hs:22:10

-type instance D Int b = String 	-- Defined at T4175.hs:19:10

-type family E a :: *

-  where

-      E () = Bool

-      E Int = String

-  	-- Defined at T4175.hs:24:1

-data () = () 	-- Defined in ‘GHC.Tuple’

-instance C () -- Defined at T4175.hs:21:10

-instance Bounded () -- Defined in ‘GHC.Enum’

-instance Enum () -- Defined in ‘GHC.Enum’

-instance Eq () -- Defined in ‘GHC.Classes’

-instance Ord () -- Defined in ‘GHC.Classes’

-instance Read () -- Defined in ‘GHC.Read’

-instance Show () -- Defined in ‘GHC.Show’

-instance Monoid () -- Defined in ‘GHC.Base’

-type instance D () a = Bool 	-- Defined at T4175.hs:22:10

-data instance B () = MkB 	-- Defined at T4175.hs:13:15

-data Maybe a = Nothing | Just a 	-- Defined in ‘GHC.Base’

-instance Eq a => Eq (Maybe a) -- Defined in ‘GHC.Base’

-instance Monad Maybe -- Defined in ‘GHC.Base’

-instance Functor Maybe -- Defined in ‘GHC.Base’

-instance Ord a => Ord (Maybe a) -- Defined in ‘GHC.Base’

-instance Read a => Read (Maybe a) -- Defined in ‘GHC.Read’

-instance Show a => Show (Maybe a) -- Defined in ‘GHC.Show’

-instance Applicative Maybe -- Defined in ‘GHC.Base’

-instance Foldable Maybe -- Defined in ‘Data.Foldable’

-instance Traversable Maybe -- Defined in ‘Data.Traversable’

-instance Monoid a => Monoid (Maybe a) -- Defined in ‘GHC.Base’

-type instance A (Maybe a) a = a 	-- Defined at T4175.hs:9:15

-data Int = I# Int# 	-- Defined in ‘GHC.Types’

-instance C Int -- Defined at T4175.hs:18:10

-instance Bounded Int -- Defined in ‘GHC.Enum’

-instance Enum Int -- Defined in ‘GHC.Enum’

-instance Eq Int -- Defined in ‘GHC.Classes’

-instance Integral Int -- Defined in ‘GHC.Real’

-instance Num Int -- Defined in ‘GHC.Num’

-instance Ord Int -- Defined in ‘GHC.Classes’

-instance Read Int -- Defined in ‘GHC.Read’

-instance Real Int -- Defined in ‘GHC.Real’

-instance Show Int -- Defined in ‘GHC.Show’

-type instance D Int b = String 	-- Defined at T4175.hs:19:10

-type instance A Int Int = () 	-- Defined at T4175.hs:8:15

-class Z a 	-- Defined at T4175.hs:28:1

-instance F (Z a) -- Defined at T4175.hs:31:10

+type family A a b :: * 	-- Defined at T4175.hs:7:1
+type instance A (Maybe a) a = a 	-- Defined at T4175.hs:9:15
+type instance A Int Int = () 	-- Defined at T4175.hs:8:15
+type instance A (B a) b = () 	-- Defined at T4175.hs:10:15
+data family B a 	-- Defined at T4175.hs:12:1
+instance G B -- Defined at T4175.hs:34:10
+data instance B () = MkB 	-- Defined at T4175.hs:13:15
+type instance A (B a) b = () 	-- Defined at T4175.hs:10:15
+class C a where
+  type family D a b :: *
+  	-- Defined at T4175.hs:16:5
+type instance D () a = Bool 	-- Defined at T4175.hs:22:10
+type instance D Int b = String 	-- Defined at T4175.hs:19:10
+type family E a :: *
+  where
+      E () = Bool
+      E Int = String
+  	-- Defined at T4175.hs:24:1
+data () = () 	-- Defined in ‘GHC.Tuple’
+instance C () -- Defined at T4175.hs:21:10
+instance Bounded () -- Defined in ‘GHC.Enum’
+instance Enum () -- Defined in ‘GHC.Enum’
+instance Eq () -- Defined in ‘GHC.Classes’
+instance Ord () -- Defined in ‘GHC.Classes’
+instance Read () -- Defined in ‘GHC.Read’
+instance Show () -- Defined in ‘GHC.Show’
+instance Monoid () -- Defined in ‘GHC.Base’
+type instance D () a = Bool 	-- Defined at T4175.hs:22:10
+data instance B () = MkB 	-- Defined at T4175.hs:13:15
+data Maybe a = Nothing | Just a 	-- Defined in ‘GHC.Base’
+instance Eq a => Eq (Maybe a) -- Defined in ‘GHC.Base’
+instance Monad Maybe -- Defined in ‘GHC.Base’
+instance Functor Maybe -- Defined in ‘GHC.Base’
+instance Ord a => Ord (Maybe a) -- Defined in ‘GHC.Base’
+instance Read a => Read (Maybe a) -- Defined in ‘GHC.Read’
+instance Show a => Show (Maybe a) -- Defined in ‘GHC.Show’
+instance Applicative Maybe -- Defined in ‘GHC.Base’
+instance Foldable Maybe -- Defined in ‘Data.Foldable’
+instance Traversable Maybe -- Defined in ‘Data.Traversable’
+instance Monoid a => Monoid (Maybe a) -- Defined in ‘GHC.Base’
+type instance A (Maybe a) a = a 	-- Defined at T4175.hs:9:15
+data Int = I# Int# 	-- Defined in ‘GHC.Types’
+instance C Int -- Defined at T4175.hs:18:10
+instance Bounded Int -- Defined in ‘GHC.Enum’
+instance Enum Int -- Defined in ‘GHC.Enum’
+instance Eq Int -- Defined in ‘GHC.Classes’
+instance Integral Int -- Defined in ‘GHC.Real’
+instance Num Int -- Defined in ‘GHC.Num’
+instance Ord Int -- Defined in ‘GHC.Classes’
+instance Read Int -- Defined in ‘GHC.Read’
+instance Real Int -- Defined in ‘GHC.Real’
+instance Show Int -- Defined in ‘GHC.Show’
+type instance D Int b = String 	-- Defined at T4175.hs:19:10
+type instance A Int Int = () 	-- Defined at T4175.hs:8:15
+class Z a 	-- Defined at T4175.hs:28:1
+instance F (Z a) -- Defined at T4175.hs:31:10
diff --git a/testsuite/tests/indexed-types/should_fail/T8550.stderr b/testsuite/tests/indexed-types/should_fail/T8550.stderr
index 1092ed247d..fb37303bce 100644
--- a/testsuite/tests/indexed-types/should_fail/T8550.stderr
+++ b/testsuite/tests/indexed-types/should_fail/T8550.stderr
@@ -1,11 +1,12 @@
 
-T8550.hs:13:12:
-    Reduction stack overflow; size = 201
-    When simplifying the following type: F ()
-    Use -freduction-depth=0 to disable this check
-    (any upper bound you could choose might fail unpredictably with
-     minor updates to GHC, so disabling the check is recommended if
-     you're sure that type checking should terminate)
-    In the expression: A
-    In the expression: seq A (return ())
-    In an equation for ‘main’: main = seq A (return ())
+T8550.hs:8:3: error:
+    • Reduction stack overflow; size = 201
+      When simplifying the following type: F ()
+      Use -freduction-depth=0 to disable this check
+      (any upper bound you could choose might fail unpredictably with
+       minor updates to GHC, so disabling the check is recommended if
+       you're sure that type checking should terminate)
+    • In the ambiguity check for ‘A’
+      To defer the ambiguity check to use sites, enable AllowAmbiguousTypes
+      In the definition of data constructor ‘A’
+      In the data type declaration for ‘A’
diff --git a/testsuite/tests/polykinds/T8132.stderr b/testsuite/tests/polykinds/T8132.stderr
index 4a1ca2b4f6..c5f56f9fbe 100644
--- a/testsuite/tests/polykinds/T8132.stderr
+++ b/testsuite/tests/polykinds/T8132.stderr
@@ -1,3 +1,4 @@
 
-T8132.hs:6:10: error:
-    Class ‘Typeable’ does not support user-specified instances
+T8132.hs:6:1: error:
+    • Class ‘Typeable’ does not support user-specified instances
+    • In the instance declaration for ‘Typeable K’
diff --git a/testsuite/tests/rename/should_compile/T4003A.hs-boot b/testsuite/tests/rename/should_compile/T4003A.hs-boot
index a615301e57..04902ddc62 100644
--- a/testsuite/tests/rename/should_compile/T4003A.hs-boot
+++ b/testsuite/tests/rename/should_compile/T4003A.hs-boot
@@ -4,5 +4,4 @@ import Data.Data
 
 data HsExpr i
 
-instance Typeable HsExpr
 instance Data i => Data (HsExpr i)
diff --git a/testsuite/tests/roles/should_compile/T8958.stderr b/testsuite/tests/roles/should_compile/T8958.stderr
index f88557eafc..982686868f 100644
--- a/testsuite/tests/roles/should_compile/T8958.stderr
+++ b/testsuite/tests/roles/should_compile/T8958.stderr
@@ -12,9 +12,9 @@ TYPE CONSTRUCTORS
 COERCION AXIOMS
   axiom T8958.N:Map :: Map k v = [(k, v)] -- Defined at T8958.hs:13:1
 INSTANCES
-  instance [incoherent] Nominal a -- Defined at T8958.hs:7:10
   instance [incoherent] Representational a
     -- Defined at T8958.hs:10:10
+  instance [incoherent] Nominal a -- Defined at T8958.hs:7:10
 Dependent modules: []
 Dependent packages: [base-4.9.0.0, ghc-prim-0.5.0.0,
                      integer-gmp-1.0.0.1]
diff --git a/testsuite/tests/th/T1835.stdout b/testsuite/tests/th/T1835.stdout
index 5b21c0352c..7d34ae01f0 100644
--- a/testsuite/tests/th/T1835.stdout
+++ b/testsuite/tests/th/T1835.stdout
@@ -1,8 +1,8 @@
 class GHC.Classes.Eq a_0 => Main.MyClass (a_0 :: *)
-instance Main.MyClass Main.Foo
+instance GHC.Classes.Ord a_1 => Main.MyClass (Main.Quux2 a_1)
+instance GHC.Classes.Eq a_2 => Main.MyClass (Main.Quux a_2)
 instance Main.MyClass Main.Baz
-instance GHC.Classes.Eq a_1 => Main.MyClass (Main.Quux a_1)
-instance GHC.Classes.Ord a_2 => Main.MyClass (Main.Quux2 a_2)
+instance Main.MyClass Main.Foo
 True
 True
 True
diff --git a/testsuite/tests/typecheck/should_compile/T11348.hs b/testsuite/tests/typecheck/should_compile/T11348.hs
new file mode 100644
index 0000000000..2548dbdab7
--- /dev/null
+++ b/testsuite/tests/typecheck/should_compile/T11348.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE TypeInType #-}
+
+module T11348 where
+
+import Data.Kind
+import Data.Proxy
+
+type family TrivialFamily t :: Type
+type instance TrivialFamily (t :: Type) = Bool
+
+data R where
+    R :: Proxy Bool -> R
+
+type ProblemType t = 'R ('Proxy :: Proxy (TrivialFamily t))
diff --git a/testsuite/tests/typecheck/should_compile/all.T b/testsuite/tests/typecheck/should_compile/all.T
index 8046fa34fc..ebc68eb941 100644
--- a/testsuite/tests/typecheck/should_compile/all.T
+++ b/testsuite/tests/typecheck/should_compile/all.T
@@ -513,3 +513,4 @@ test('T11512', normal, compile, [''])
 test('T11754', normal, compile, [''])
 test('T11811', normal, compile, [''])
 test('T11793', normal, compile, [''])
+test('T11348', normal, compile, [''])
diff --git a/testsuite/tests/typecheck/should_fail/T6018fail.stderr b/testsuite/tests/typecheck/should_fail/T6018fail.stderr
index 95b9d1bb3e..c20c9ecc89 100644
--- a/testsuite/tests/typecheck/should_fail/T6018fail.stderr
+++ b/testsuite/tests/typecheck/should_fail/T6018fail.stderr
@@ -62,7 +62,7 @@ T6018fail.hs:59:10: error:
         (i.e. ones independent of the class type variables)
         must be distinct type variables
       Expected: PolyKindVarsF '[]
-      Actual:   PolyKindVarsF '[]
+        Actual: PolyKindVarsF '[]
       Use -fprint-explicit-kinds to see the kind arguments
     • In the type instance declaration for ‘PolyKindVarsF’
       In the instance declaration for ‘PolyKindVarsC '[]’
@@ -91,10 +91,10 @@ T6018fail.hs:70:15: error:
       forall k (a :: k) (b :: k).
         Gc a b = Int -- Defined at T6018fail.hs:70:15
 
-T6018fail.hs:75:15: error:
+T6018fail.hs:74:15: error:
     Type family equations violate injectivity annotation:
-      F1 (Maybe a) = Maybe (GF2 a) -- Defined at T6018fail.hs:75:15
       F1 [a] = Maybe (GF1 a) -- Defined at T6018fail.hs:74:15
+      F1 (Maybe a) = Maybe (GF2 a) -- Defined at T6018fail.hs:75:15
 
 T6018fail.hs:87:15: error:
     Type family equation violates injectivity annotation.
diff --git a/testsuite/tests/typecheck/should_fail/tcfail211.stderr b/testsuite/tests/typecheck/should_fail/tcfail211.stderr
index 614aaf59fa..7a5053a092 100644
--- a/testsuite/tests/typecheck/should_fail/tcfail211.stderr
+++ b/testsuite/tests/typecheck/should_fail/tcfail211.stderr
@@ -1,6 +1,12 @@
 
-tcfail211.hs:5:1:
-    Illegal implicit parameter ‘?imp::Int’
-    In the context: ?imp::Int
-    While checking the super-classes of class ‘D’
-    In the class declaration for ‘D’
+tcfail211.hs:5:1: error:
+    • Illegal implicit parameter ‘?imp::Int’
+    • In the context: ?imp::Int
+      While checking the super-classes of class ‘D’
+      In the class declaration for ‘D’
+
+tcfail211.hs:8:10: error:
+    • Illegal implicit parameter ‘?imp::Int’
+    • In the context: ?imp::Int
+      While checking an instance declaration
+      In the instance declaration for ‘D Int’