[csa] Refactor promises API

src/builtins/builtins-promise.h

 // Copyright 2016 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/code-stub-assembler.h"
 
 namespace v8 {
 namespace internal {
 
 typedef compiler::Node Node;
 typedef CodeStubAssembler::ParameterMode ParameterMode;
 typedef compiler::CodeAssemblerState CodeAssemblerState;
 
 class PromiseBuiltinsAssembler : public CodeStubAssembler {
  public:
   explicit PromiseBuiltinsAssembler(CodeAssemblerState* state)
       : CodeStubAssembler(state) {}
 
-  Node* AllocateAndInitPromise(Node* context, Node* parent);
+  // These allocate and initialize a promise with pending state and
+  // undefined fields.
+  //
+  // This uses undefined as the parent promise for the promise init
+  // hook.
+  Node* AllocateAndInitJSPromise(Node* context);
+  // This uses the given parent as the parent promise for the promise
+  // init hook.
+  Node* AllocateAndInitJSPromise(Node* context, Node* parent);
+
+  // This allocates and initializes a promise with the given state and
+  // fields.
+  Node* AllocateAndSetJSPromise(Node* context, Node* status, Node* result);
 
   Node* ThrowIfNotJSReceiver(Node* context, Node* value,
                              MessageTemplate::Template msg_template);
 
   Node* SpeciesConstructor(Node* context, Node* object,
                            Node* default_constructor);
 
   Node* PromiseHasHandler(Node* promise);
 
   void PromiseSetHasHandler(Node* promise);
@@ skipping 20 matching lines @@
                                                Node* native_context);
 
   std::pair<Node*, Node*> CreatePromiseResolvingFunctions(
       Node* promise, Node* native_context, Node* promise_context);
 
   Node* CreatePromiseGetCapabilitiesExecutorContext(Node* native_context,
                                                     Node* promise_capability);
 
   Node* NewPromiseCapability(Node* context, Node* constructor,
                              Node* debug_event = nullptr);
+
+ protected:
+  void PromiseInit(Node* promise);
+
+ private:
+  Node* AllocateJSPromise(Node* context);
 };
 
 }  // namespace internal
 }  // namespace v8