[csa] Refactor promises API

src/builtins/builtins-promise.h

Index: src/builtins/builtins-promise.h
diff --git a/src/builtins/builtins-promise.h b/src/builtins/builtins-promise.h
index 8615f967949b59a6b2fbb9f502e77f9517187162..f3d1e9544488162d89cb5f47671525fe695201d8 100644
--- a/src/builtins/builtins-promise.h
+++ b/src/builtins/builtins-promise.h
@@ -16,7 +16,11 @@ class PromiseBuiltinsAssembler : public CodeStubAssembler {
   explicit PromiseBuiltinsAssembler(CodeAssemblerState* state)
       : CodeStubAssembler(state) {}
 
-  Node* AllocateAndInitPromise(Node* context, Node* parent);
+  // These are just wrapper functions over the CSA counterparts and
+  // call out to the init promise hook.

[adamk, 2017/01/03 18:23:06]

This is really a question for caitp, I think, but do we ever want to allow a
builtin to allocate a promise without calling out to the promise hooks? It seems
like all promises need to flow through that code anyway.

[caitp, 2017/01/03 18:32:05]

I'm not sure if there are any situations where we're allowed to avoid the hook
call, so presumably not.

It's weird that CSA's method with the same name doesn't call the init hook, that
seems wrong to me.

+  Node* AllocateAndInitJSPromise(Node* context, Node* parent);
+  Node* AllocateAndSetJSPromise(Node* context, Node* status, Node* result,
+                                Node* parent);
 
   Node* ThrowIfNotJSReceiver(Node* context, Node* value,
                              MessageTemplate::Template msg_template);