Merge commit 'fdab756331f3' from llvm.org/release/11.x into apple/stable/20200714

Author: git apple-llvm automerger

clang/lib/Sema/SemaDecl.cpp

@@ -9648,6 +9648,7 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
             NewFD->addAttr(BuiltinAttr::CreateImplicit(Context, BuiltinID));
           } else {
             ASTContext::GetBuiltinTypeError Error;
+            LookupPredefedObjCSuperType(*this, S, NewFD->getIdentifier());
             QualType BuiltinType = Context.GetBuiltinType(BuiltinID, Error);
 
             if (!Error && !BuiltinType.isNull() &&

clang/test/SemaObjCXX/builtin-objcsuper.mm

@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -verify %s
+// expected-no-diagnostics
+
+// objc_super has special lookup rules for compatibility with macOS headers, so
+// the following should compile.
+struct objc_super {};
+extern "C" id objc_msgSendSuper(struct objc_super *super, SEL op, ...);
+extern "C" void objc_msgSendSuper_stret(struct objc_super *super, SEL op, ...);