[clang] [llvm] [AMDGPU][clang][CodeGen][opt] Add late-resolved feature identifying predicates (PR #134016)

[Erich Keane via cfe-commits]

================
@@ -581,6 +581,9 @@ llvm::Type *CodeGenTypes::ConvertType(QualType T) {
   case BuiltinType::Id:                                                        \
     return llvm::TargetExtType::get(getLLVMContext(), "amdgcn.named.barrier",  \
                                     {}, {Scope});
+#define AMDGPU_FEATURE_PREDICATE_TYPE(Name, Id, SingletonId, Width, Align)     \
+  case BuiltinType::Id:                                                        \
+    return llvm::IntegerType::getInt1Ty(getLLVMContext());
----------------
erichkeane wrote:

Why an int-1 type instead of 'bool' type?  Won't this cause problems if it is returned? Are we making sure we force casts correctly, else this is going to be a bug factory when emitting it.

https://github.com/llvm/llvm-project/pull/134016