Remove unnecessary default cases in switches that cover all enum values.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147855 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AsmParser/LLParser.cpp

@@ -2438,7 +2438,6 @@ bool LLParser::ConvertValIDToValue(Type *Ty, ValID &ID, Value *&V,
     return Error(ID.Loc, "functions are not values, refer to them as pointers");
 
   switch (ID.Kind) {
-  default: llvm_unreachable("Unknown ValID!");
   case ValID::t_LocalID:
     if (!PFS) return Error(ID.Loc, "invalid use of function-local name");
     V = PFS->GetVal(ID.UIntVal, Ty, ID.Loc);