[HLSL] Implement D3DCOLORtoUBYTE4 intrinsic#122202

inbelic merged 4 commits intollvm:mainllvm/llvm-project:mainfrom

Icohedron:D3DCOLORtoUBYTE4-implIcohedron/llvm-project:D3DCOLORtoUBYTE4-implCopy head branch name to clipboard