[promises] Move CreateResolvingFunctions to c++

src/factory.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/factory.h"
 
 #include "src/accessors.h"
 #include "src/allocation-site-scopes.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 944 matching lines @@
   Handle<FixedArray> array = NewFixedArray(scope_info->ContextLength());
   array->set_map_no_write_barrier(*block_context_map());
   Handle<Context> context = Handle<Context>::cast(array);
   context->set_closure(*function);
   context->set_previous(*previous);
   context->set_extension(*scope_info);
   context->set_native_context(previous->native_context());
   return context;
 }
 
+Handle<Context> Factory::NewPromiseResolvingFunctionContext(
+    Handle<JSFunction> function, Handle<Cell> already_visited,
+    Handle<JSObject> promise, Handle<Object> debug_event) {
+  Handle<FixedArray> array = NewFixedArray(Context::MIN_CONTEXT_SLOTS + 3);
+  array->set_map_no_write_barrier(*function_context_map());
+  Handle<Context> context = Handle<Context>::cast(array);
+  context->set_closure(*function);
+  context->set_previous(function->context());
+  context->set_extension(*the_hole_value());
+  context->set_native_context(function->native_context());
+  context->set(4, *already_visited);
+  context->set(5, *promise);
+  context->set(6, *debug_event);

[adamk, 2016/11/08 18:09:55]

Looks like if you let the caller do the setting, you could have those enums
defined only in builtins-promise.cc (and pass in the length too).

[gsathya, 2016/11/08 20:03:19]

NewDebugEvaluateContext and NewCatchContext have a magic length, so I'm leaving
the length here as such. But, I guess they set all the values in the function
itself, so it's easier to figure out what the magic number means.  Let me know
if you'd rather have me pass it in as an argument.

+  return context;
+}
 
 Handle<Struct> Factory::NewStruct(InstanceType type) {
   CALL_HEAP_FUNCTION(
       isolate(),
       isolate()->heap()->AllocateStruct(type),
       Struct);
 }
 
 Handle<PromiseResolveThenableJobInfo> Factory::NewPromiseResolveThenableJobInfo(
     Handle<JSReceiver> thenable, Handle<JSReceiver> then,
@@ skipping 1732 matching lines @@
       Handle<JSFixedArrayIterator>::cast(NewJSObjectFromMap(map));
   iterator->set_initial_next(*next);
   iterator->set_array(*array);
   iterator->set_index(0);
   iterator->InObjectPropertyAtPut(JSFixedArrayIterator::kNextIndex, *next);
   return iterator;
 }
 
 }  // namespace internal
 }  // namespace v8