[clang] [AArch64] Add MSVC mangling for the __mfp8 type (PR #124968)

[Momchil Velikov via cfe-commits]

================
@@ -2808,6 +2812,7 @@ void MicrosoftCXXNameMangler::mangleType(const BuiltinType *T, Qualifiers,
 
 #define SVE_TYPE(Name, Id, SingletonId) \
   case BuiltinType::Id:
+#define SVE_SCALAR_TYPE(Name, MangledName, Id, SingletonId, Bits)
----------------
momchil-velikov wrote:

It can be done. Doesn't mean it's a good idea.
With the proposed change all the SVE types will fall-through to the `SVE_SCALAR_TYPE` case, or worse
some will and some won't, depending on the relative order in `AArch64SVEACLETypes.def`.
That can work by including the `.def` file twice, once for the scalar type and once for all the SVE types.
Or use a `default:` for the unsupported cases, but I decided to stick to the existing style.

https://github.com/llvm/llvm-project/pull/124968