[clang] [llvm] [DirectX] Add isinf f16 emulation for SM6.8 and lower (PR #156932)

[Sarah Spall via llvm-commits]

================
@@ -51,6 +51,43 @@ static bool resourceAccessNeeds64BitExpansion(Module *M, Type *OverloadTy,
   return ScalarTy->isDoubleTy() || ScalarTy->isIntegerTy(64);
 }
 
+static Value *expand16BitIsInf(CallInst *Orig) {
+  Module *M = Orig->getModule();
+  if (M->getTargetTriple().getDXILVersion() >= VersionTuple(1, 9))
+    return nullptr;
+
+  Value *Val = Orig->getOperand(0);
+  Type *ValTy = Val->getType();
+  if (!(ValTy->isHalfTy() ||
----------------
spall wrote:

Could you use getScalarType() here to prevent casting the vector?
```
!ValTy->getScalarType()->isHalfTy()
```

https://github.com/llvm/llvm-project/pull/156932