AST: Replace a getSelfInterfaceType() with TheSelfType

Author: slavapestov

lib/AST/RequirementEnvironment.cpp

@@ -85,16 +85,13 @@ RequirementEnvironment::RequirementEnvironment(
   // parameters of the requirement into a combined context that provides the
   // type parameters of the conformance context and the parameters of the
   // requirement.
-  auto selfType = cast<GenericTypeParamType>(
-      proto->getSelfInterfaceType()->getCanonicalType());
-
   reqToWitnessThunkSigMap = SubstitutionMap::get(reqSig,
-    [selfType, substConcreteType, depth, covariantSelf, &ctx]
+    [substConcreteType, depth, covariantSelf, &ctx]
     (SubstitutableType *type) -> Type {
       // If the conforming type is a class, the protocol 'Self' maps to
       // the class-constrained 'Self'. Otherwise, it maps to the concrete
       // type.
-      if (type->isEqual(selfType)) {
+      if (type->isEqual(ctx.TheSelfType)) {
         if (covariantSelf)
           return ctx.TheSelfType;
         return substConcreteType;
@@ -114,11 +111,11 @@ RequirementEnvironment::RequirementEnvironment(
       }
       return substGenericParam;
     },
-    [selfType, substConcreteType, conformance, conformanceDC, covariantSelf, &ctx](
+    [substConcreteType, conformance, conformanceDC, covariantSelf, &ctx](
         CanType type, Type replacement, ProtocolDecl *proto)
           -> ProtocolConformanceRef {
       // The protocol 'Self' conforms concretely to the conforming type.
-      if (type->isEqual(selfType)) {
+      if (type->isEqual(ctx.TheSelfType)) {
         ASSERT(covariantSelf || replacement->isEqual(substConcreteType));
 
         if (conformance) {