Textual SIL was sometimes ambiguous when SILDeclRefs were used, because the textual representation of SILDeclRefs was the same for functions that have the same name, but different signatures.
Textual SIL was sometimes ambiguous when SILDeclRefs were used, because the textual representation of SILDeclRefs was the same for functions that have the same name, but different signatures.
If a generic parameter was substituted for Self, we have to be careful
to not erase Self.Type down to a concrete metatype.
Also, teach the devirtualizer that a metatype of Self type does not
have an exact static type.