[clang] [libcxx] [Clang] Add __builtin_invoke and use it in libc++ (PR #116709)

[Aaron Ballman via cfe-commits]

================
@@ -5406,6 +5408,99 @@ ExprResult Sema::ConvertVectorExpr(Expr *E, TypeSourceInfo *TInfo,
                                    RParenLoc, CurFPFeatureOverrides());
 }
 
+ExprResult Sema::BuiltinInvoke(CallExpr *TheCall) {
+  SourceLocation Loc = TheCall->getBeginLoc();
+  auto Args = MutableArrayRef(TheCall->getArgs(), TheCall->getNumArgs());
+  assert(llvm::none_of(Args,
+                       [](Expr *Arg) { return Arg->isTypeDependent(); }));
+
+  if (Args.size() == 0) {
+    Diag(TheCall->getBeginLoc(), diag::err_typecheck_call_too_few_args_at_least)
+        << /*callee_type=*/0 << /*min_arg_count=*/1 << /*actual_arg_count=*/0
+        << /*is_non_object=*/0 << TheCall->getSourceRange();
+    return ExprError();
+  }
+
+  auto FuncT = Args[0]->getType();
+
+  if (auto *MPT = FuncT->getAs<MemberPointerType>()) {
+    if (Args.size() < 2) {
+      Diag(TheCall->getBeginLoc(),
+           diag::err_typecheck_call_too_few_args_at_least)
+          << /*callee_type=*/0 << /*min_arg_count=*/2 << /*actual_arg_count=*/1
+          << /*is_non_object=*/0 << TheCall->getSourceRange();
+      return ExprError();
+    }
+
+    auto *MemPtrClass = MPT->getQualifier()->getAsType();
+    auto ObjectT = Args[1]->getType();
+
+    if (MPT->isMemberDataPointer() && checkArgCount(TheCall, 2))
+      return ExprError();
+
+    ExprResult ObjectArg = [&]() -> ExprResult {
+      // (1.1): (t1.*f)(t2, …, tN) when f is a pointer to a member function of a
----------------
AaronBallman wrote:

```suggestion
      // (1.1): (t1.*f)(t2, ..., tN) when f is a pointer to a member function of a
```
Replacing non-ASCII with ASCII.

https://github.com/llvm/llvm-project/pull/116709