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

[Farzon Lotfi via cfe-commits]

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@@ -35,8 +35,10 @@ static constexpr Builtin::Info BuiltinInfos[] = {
 static_assert(std::size(BuiltinInfos) == NumBuiltins);
 
 llvm::SmallVector<Builtin::InfosShard>
-SPIRVTargetInfo::getTargetBuiltins() const {
-  return {{&BuiltinStrings, BuiltinInfos}};
+BaseSPIRTargetInfo::getTargetBuiltins() const {
+  if (getTriple().isSPIRV())
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farzonl wrote:

if you are using this to extend  the builtins to spirv32/spirv64 I have concerns that not all builtins will be valid for those targets. For example `__builtin_spirv_reflect` is only valid when targeting spirv because thats the target that enables GLSL extentions. It is not valid for spirv32/64 because there is no equivalent opencl extention. To expose across all targets without exposing builtins that break could be tricky and might require special codegen to emulate the behavior of other targets. It might be simpler to just do a new tablegen file for spirv32/spriv64.

https://github.com/llvm/llvm-project/pull/137805