[clang] Adding `asuint` implementation to hlsl (PR #107292)

[Justin Bogner via cfe-commits]

================
@@ -0,0 +1,35 @@
+//===----- hlsl_intrinsics.h - HLSL definitions for intrinsics ----------===//
----------------
bogner wrote:

This comment needs updating.

https://github.com/llvm/llvm-project/pull/107292