Major patch to introduce TyConBinder

Before this patch, following the TypeInType innovations,
each TyCon had two lists:
  - tyConBinders :: [TyBinder]
  - tyConTyVars  :: [TyVar]

They were in 1-1 correspondence and contained
overlapping information.  More broadly, there were many
places where we had to pass around this pair of lists,
instead of a single list.

This commit tidies all that up, by having just one list of
binders in a TyCon:

  - tyConBinders :: [TyConBinder]

The new data types look like this:

  Var.hs:
     data TyVarBndr tyvar vis = TvBndr tyvar vis
     data VisibilityFlag = Visible | Specified | Invisible
     type TyVarBinder = TyVarBndr TyVar VisibilityFlag

  TyCon.hs:
     type TyConBinder = TyVarBndr TyVar TyConBndrVis

     data TyConBndrVis
       = NamedTCB VisibilityFlag
       | AnonTCB

  TyCoRep.hs:
     data TyBinder
       = Named TyVarBinder
       | Anon Type

Note that Var.TyVarBdr has moved from TyCoRep and has been
made polymorphic in the tyvar and visiblity fields:

     type TyVarBinder = TyVarBndr TyVar VisibilityFlag
        -- Used in ForAllTy
     type TyConBinder = TyVarBndr TyVar TyConBndrVis
        -- Used in TyCon

     type IfaceForAllBndr  = TyVarBndr IfaceTvBndr VisibilityFlag
     type IfaceTyConBinder = TyVarBndr IfaceTvBndr TyConBndrVis
         -- Ditto, in interface files

There are a zillion knock-on changes, but everything
arises from these types.  It was a bit fiddly to get the
module loops to work out right!

Some smaller points
~~~~~~~~~~~~~~~~~~~
* Nice new functions
    TysPrim.mkTemplateKiTyVars
    TysPrim.mkTemplateTyConBinders
  which help you make the tyvar binders for dependently-typed
  TyCons.  See comments with their definition.

* The change showed up a bug in TcGenGenerics.tc_mkRepTy, where the code
  was making an assumption about the order of the kind variables in the
  kind of GHC.Generics.(:.:).  I fixed this; see TcGenGenerics.mkComp.

2 files changed, 37 insertions, 37 deletions

diff --git a/testsuite/tests/gadt/gadt13.stderr b/testsuite/tests/gadt/gadt13.stderr
index 06b1f9c720..e304430b51 100644
--- a/testsuite/tests/gadt/gadt13.stderr
+++ b/testsuite/tests/gadt/gadt13.stderr
@@ -1,17 +1,17 @@
-

-gadt13.hs:15:13: error:

-    • Couldn't match expected type ‘t’

-                  with actual type ‘String -> [Char]’

-        ‘t’ is untouchable

-          inside the constraints: t1 ~ Int

-          bound by a pattern with constructor: I :: Int -> Term Int,

-                   in an equation for ‘shw’

-          at gadt13.hs:15:6-8

-      ‘t’ is a rigid type variable bound by

-        the inferred type of shw :: Term t1 -> t at gadt13.hs:15:1-30

-      Possible fix: add a type signature for ‘shw’

-    • Possible cause: ‘(.)’ is applied to too many arguments

-      In the expression: ("I " ++) . shows t

-      In an equation for ‘shw’: shw (I t) = ("I " ++) . shows t

-    • Relevant bindings include

-        shw :: Term t1 -> t (bound at gadt13.hs:15:1)

+
+gadt13.hs:15:13: error:
+    • Couldn't match expected type ‘t’
+                  with actual type ‘String -> [Char]’
+        ‘t’ is untouchable
+          inside the constraints: a ~ Int
+          bound by a pattern with constructor: I :: Int -> Term Int,
+                   in an equation for ‘shw’
+          at gadt13.hs:15:6-8
+      ‘t’ is a rigid type variable bound by
+        the inferred type of shw :: Term a -> t at gadt13.hs:15:1-30
+      Possible fix: add a type signature for ‘shw’
+    • Possible cause: ‘(.)’ is applied to too many arguments
+      In the expression: ("I " ++) . shows t
+      In an equation for ‘shw’: shw (I t) = ("I " ++) . shows t
+    • Relevant bindings include
+        shw :: Term a -> t (bound at gadt13.hs:15:1)
diff --git a/testsuite/tests/gadt/gadt7.stderr b/testsuite/tests/gadt/gadt7.stderr
index 6e1effa067..e66226eaea 100644
--- a/testsuite/tests/gadt/gadt7.stderr
+++ b/testsuite/tests/gadt/gadt7.stderr
@@ -1,20 +1,20 @@
-

-gadt7.hs:16:38: error:

-    • Couldn't match expected type ‘t’ with actual type ‘t1’

-        ‘t’ is untouchable

-          inside the constraints: t2 ~ Int

-          bound by a pattern with constructor: K :: T Int,

-                   in a case alternative

-          at gadt7.hs:16:33

-      ‘t’ is a rigid type variable bound by

-        the inferred type of i1b :: T t2 -> t1 -> t at gadt7.hs:16:1-44

-      ‘t1’ is a rigid type variable bound by

-        the inferred type of i1b :: T t2 -> t1 -> t at gadt7.hs:16:1-44

-      Possible fix: add a type signature for ‘i1b’

-    • In the expression: y1

-      In a case alternative: K -> y1

-      In the expression: case t1 of { K -> y1 }

-    • Relevant bindings include

-        y1 :: t1 (bound at gadt7.hs:16:16)

-        y :: t1 (bound at gadt7.hs:16:7)

-        i1b :: T t2 -> t1 -> t (bound at gadt7.hs:16:1)

+
+gadt7.hs:16:38: error:
+    • Couldn't match expected type ‘t’ with actual type ‘t1’
+        ‘t’ is untouchable
+          inside the constraints: a ~ Int
+          bound by a pattern with constructor: K :: T Int,
+                   in a case alternative
+          at gadt7.hs:16:33
+      ‘t’ is a rigid type variable bound by
+        the inferred type of i1b :: T a -> t1 -> t at gadt7.hs:16:1-44
+      ‘t1’ is a rigid type variable bound by
+        the inferred type of i1b :: T a -> t1 -> t at gadt7.hs:16:1-44
+      Possible fix: add a type signature for ‘i1b’
+    • In the expression: y1
+      In a case alternative: K -> y1
+      In the expression: case t1 of { K -> y1 }
+    • Relevant bindings include
+        y1 :: t1 (bound at gadt7.hs:16:16)
+        y :: t1 (bound at gadt7.hs:16:7)
+        i1b :: T a -> t1 -> t (bound at gadt7.hs:16:1)