SILGen: Catch an unnecessary mapTypeIntoContext() call

Author: slavapestov

lib/SIL/SILFunction.cpp

@@ -171,6 +171,8 @@ SILType SILFunction::mapTypeIntoContext(SILType type) const {
 
 SILType GenericEnvironment::mapTypeIntoContext(SILModule &M,
                                                SILType type) const {
+  assert(!type.hasArchetype());
+
   auto genericSig = getGenericSignature()->getCanonicalSignature();
   return type.subst(M,
                     QueryInterfaceTypeSubstitutions(this),

lib/SILGen/SILGenPoly.cpp

@@ -1063,7 +1063,6 @@ namespace {
                                        outputOrigType, outputTupleType,
                                        loweredTy);
 
-        optionalTy = SGF.F.mapTypeIntoContext(optionalTy);
         auto optional = SGF.B.createEnum(Loc, payload.getValue(),
                                          someDecl, optionalTy);
         return ManagedValue(optional, payload.getCleanup());