ParseSIL: handle ReferenceStorageType

It doesn't make sense that we permit a `ReferenceStorageType` to be
substituted for a generic parameter, since I don't know whether any
valid Swift code would ever actually construct such SIL.

But there are some hand-written SIL test cases that do it anyway, for
unconstrained generic parameters. Since now even those get protocol
requirements with NoncopyableGenerics, just look at the referent type in
ParseSIL.

Author: kavon

lib/SIL/Parser/ParseSIL.cpp

@@ -1759,6 +1759,7 @@ static bool getConformancesForSubstitution(Parser &P,
               SourceLoc loc,
               SmallVectorImpl<ProtocolConformanceRef> &conformances) {
   auto M = P.SF.getParentModule();
+  subReplacement = subReplacement->getReferenceStorageReferent();
 
   for (auto protoDecl : protocols) {
     auto conformance = M->lookupConformance(subReplacement, protoDecl);
@@ -1814,6 +1815,7 @@ SubstitutionMap getApplySubstitutionsFromParsed(
       [&](CanType dependentType, Type replacementType,
           ProtocolDecl *proto) -> ProtocolConformanceRef {
         auto M = SP.P.SF.getParentModule();
+        replacementType = replacementType->getReferenceStorageReferent();
         if (auto conformance = M->lookupConformance(replacementType, proto))
           return conformance;