Break up TcRnTypes, among other modules.wip/rae/split-up-modules

This introduces three new modules:

 - basicTypes/Predicate.hs describes predicates, moving
   this logic out of Type. Predicates don't really exist
   in Core, and so don't belong in Type.

 - typecheck/TcOrigin.hs describes the origin of constraints
   and types. It was easy to remove from other modules and
   can often be imported instead of other, scarier modules.

 - typecheck/Constraint.hs describes constraints as used in
   the solver. It is taken from TcRnTypes.

No work other than module splitting is in this patch.

This is the first step toward homogeneous equality, which will
rely more strongly on predicates. And homogeneous equality is the
next step toward a dependently typed core language.

1 files changed, 1 insertions, 0 deletions

diff --git a/compiler/coreSyn/CoreUtils.hs b/compiler/coreSyn/CoreUtils.hs
index 95aae22b58..1ca5a6b438 100644
--- a/compiler/coreSyn/CoreUtils.hs
+++ b/compiler/coreSyn/CoreUtils.hs
@@ -77,6 +77,7 @@ import Id
 import IdInfo
 import PrelNames( absentErrorIdKey )
 import Type
+import Predicate
 import TyCoRep( TyCoBinder(..), TyBinder )
 import Coercion
 import TyCon