[clang][SPIRV] Add builtin for OpGenericCastToPtrExplicit and its SPIR-V friendly binding#137805

VyacheslavLevytskyy merged 2 commits intollvm:mainllvm/llvm-project:mainfrom

Naghasan:generic_cast_to_ptr_explicit_builtinNaghasan/llvm-project:generic_cast_to_ptr_explicit_builtinCopy head branch name to clipboard