[WIP] Initial CallFunctionCallback builtin.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 84630928d49ee3a256af73a9a2268d49e029d49c..ae15de94d299d644e8cfd6e7949569c7a8b15793 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -2636,40 +2636,8 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   __ Cmp(Operand(rdi, 0), factory->the_hole_value());
   __ j(not_equal, &promote_scheduled_exception);
 
-#if DEBUG
   // Check if the function returned a valid JavaScript value.
-  Label ok;
-  Register return_value = rax;
-  Register map = rcx;
-
-  __ JumpIfSmi(return_value, &ok, Label::kNear);
-  __ movp(map, FieldOperand(return_value, HeapObject::kMapOffset));
-
-  __ CmpInstanceType(map, LAST_NAME_TYPE);
-  __ j(below_equal, &ok, Label::kNear);
-
-  __ CmpInstanceType(map, FIRST_JS_RECEIVER_TYPE);
-  __ j(above_equal, &ok, Label::kNear);
-
-  __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
-  __ j(equal, &ok, Label::kNear);
-
-  __ CompareRoot(return_value, Heap::kUndefinedValueRootIndex);
-  __ j(equal, &ok, Label::kNear);
-
-  __ CompareRoot(return_value, Heap::kTrueValueRootIndex);
-  __ j(equal, &ok, Label::kNear);
-
-  __ CompareRoot(return_value, Heap::kFalseValueRootIndex);
-  __ j(equal, &ok, Label::kNear);
-
-  __ CompareRoot(return_value, Heap::kNullValueRootIndex);
-  __ j(equal, &ok, Label::kNear);
-
-  __ Abort(kAPICallReturnedInvalidObject);
-
-  __ bind(&ok);
-#endif
+  __ AssertApiCallResult(rax);
 
   if (stack_space_operand != nullptr) {
     DCHECK_EQ(stack_space, 0);
@@ -2764,6 +2732,12 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
     __ movp(context, FieldOperand(callee, JSFunction::kContextOffset));
   }
 
+  if (!this->is_store()) {
+    __ Set(rax, this->argc());
+    __ jmp(masm->isolate()->builtins()->CallFunctionCallback(),
+           RelocInfo::CODE_TARGET);
+  }
+
   // Allocate the v8::Arguments structure in the arguments' space since
   // it's not controlled by GC.
   const int kApiStackSpace = 3;