[runtime] set AsyncFunctionNext/Throw to adapt arguments

src/bootstrapper.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
@@ skipping 2453 matching lines @@
       JSFunction::SetPrototype(async_function_constructor,
                                async_function_prototype);
 
       Handle<JSFunction> async_function_next =
           SimpleInstallFunction(container, "AsyncFunctionNext",
                                 Builtins::kGeneratorPrototypeNext, 2, false);
       Handle<JSFunction> async_function_throw =
           SimpleInstallFunction(container, "AsyncFunctionThrow",
                                 Builtins::kGeneratorPrototypeThrow, 2, false);
       async_function_next->shared()->set_native(true);
+      async_function_next->shared()->set_internal_formal_parameter_count(1);

[caitp (gmail), 2016/05/18 14:38:23]

question: why do we not set internal_formal_parameter_count when we don't adapt
arguments? Isn't it necessary regardless? I think I can avoid creating the
adapter frame, so I assume I want `false` here. But maybe someone can give me
some background on this

[caitp (gmail), 2016/05/18 18:21:13]

It may be a more general / better solution to handle
SharedFunctionInfo::kDontAdaptArgumentsSentinel in
JavaScriptFrame::GetNumberOfIncomingArguments() (replacing it with
SharedFunctionInfo::length() instead? or 0?), but I don't know if that would
break anything.

       async_function_throw->shared()->set_native(true);
+      async_function_throw->shared()->set_internal_formal_parameter_count(1);
     }
   }
 }
 
 
 void Bootstrapper::ExportExperimentalFromRuntime(Isolate* isolate,
                                                  Handle<JSObject> container) {
   HandleScope scope(isolate);
 
 #define INITIALIZE_FLAG(FLAG)                                         \
@@ skipping 1291 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8