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

[Farzon Lotfi via cfe-commits]

================
@@ -387,6 +387,23 @@ float3 asin(float3);
 _HLSL_BUILTIN_ALIAS(__builtin_elementwise_asin)
 float4 asin(float4);
 
+//===----------------------------------------------------------------------===//
+// asuint builtins
+//===----------------------------------------------------------------------===//
+
+/// \fn uint asuint(T Val)
+/// \brief Interprets the bit pattern of x as an unsigned integer.
+/// \param Val The input value.
+
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_asuint)
+uint asuint(float);
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_asuint)
+uint2 asuint(float2);
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_asuint)
+uint3 asuint(float3);
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_asuint)
+uint4 asuint(float4);
+
----------------
farzonl wrote:

Need to handle the int case. and i'm thinking for the uint case maybe just return the input? we haven't done that in the header before, but the uint case doesn't warrant code gen. 

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