Add missing cases to clang switch after D141863

[krzysz00]

Summary

Turns out there's a switch on APFloat semantics in clang I wasn't
aware of, fix the build error here.

clang/lib/AST/MicrosoftMangle.cpp

void MicrosoftCXXNameMangler::mangleFloat(llvm::APFloat Number) {
   // unlikely to conflict with MSVC's scheme.
   case APFloat::S_IEEEhalf: Out << 'V'; break;
   case APFloat::S_BFloat: Out << 'W'; break;
   case APFloat::S_x87DoubleExtended: Out << 'X'; break;
   case APFloat::S_IEEEquad: Out << 'Y'; break;
   case APFloat::S_PPCDoubleDouble: Out << 'Z'; break;
   case APFloat::S_Float8E5M2:
   case APFloat::S_Float8E4M3FN:
+  case APFloat::S_Float8E5M2FNUZ:
+  case APFloat::S_Float8E4M3FNUZ:
     llvm_unreachable("Tried to mangle unexpected APFloat semantics");
   }
 
   mangleBits(Number.bitcastToAPInt());
 }
 
 void MicrosoftCXXNameMangler::mangleBits(llvm::APInt Value) {
   if (Value == 0)