Export zonkEvBinds from TcHsSyn.

Needed for constructing correct constraint-satisfying code
(particularly type class instances) in a Core-to-Core transformation.

Reviewers: simonpj, austin, bgamari

Reviewed By: austin, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2088

GHC Trac Issues: #11804

compiler/typecheck/TcHsSyn.hs

@@ -30,6 +30,7 @@ module TcHsSyn (
         emptyZonkEnv, mkEmptyZonkEnv,
         zonkTcTypeToType, zonkTcTypeToTypes, zonkTyVarOcc,
         zonkCoToCo, zonkTcKindToKind,
+        zonkEvBinds,
 
         -- * Validity checking
         checkForRepresentationPolymorphism