[llvm] [Arm64EC] Add support for `half` (PR #152843)

[Daniel Paoliello via llvm-commits]

================
@@ -316,6 +316,11 @@ ThunkArgInfo AArch64Arm64ECCallLowering::canonicalizeThunkType(
                         ThunkArgTranslation::PointerIndirection};
   };
 
+  if (T->isHalfTy()) {
+    Out << "h";
----------------
dpaoliello wrote:

I'm going to defer to @pmsjt here, since he owns the ABI and related documentation at <https://learn.microsoft.com/en-us/windows/arm/arm64ec-abi>
Unfortunately, he's out for August...

https://github.com/llvm/llvm-project/pull/152843