[runtime] set AsyncFunctionNext/Throw to adapt arguments

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index b96b834505c0ab62d528d74add2207a4d218e2e7..32d024dd785eff8008835636dab050dba90984fa 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -2471,7 +2471,9 @@ void Bootstrapper::ExportFromRuntime(Isolate* isolate,
           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);
     }
   }
 }