[refactor] Separate generated builtins and C++ builtins into separate files

src/builtins/builtins-promise-gen.cc

 // 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/builtins/builtins-constructor.h"
 #include "src/builtins/builtins-promise.h"
-#include "src/builtins/builtins-constructor.h"
-#include "src/builtins/builtins-utils.h"
+#include "src/builtins/builtins-utils-gen.h"
 #include "src/builtins/builtins.h"
 #include "src/code-factory.h"
 #include "src/code-stub-assembler.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 
+using compiler::Node;
+
 Node* PromiseBuiltinsAssembler::AllocateJSPromise(Node* context) {
   Node* const native_context = LoadNativeContext(context);
   Node* const promise_fun =
       LoadContextElement(native_context, Context::PROMISE_FUNCTION_INDEX);
   Node* const initial_map =
       LoadObjectField(promise_fun, JSFunction::kPrototypeOrInitialMapOffset);
   Node* const instance = AllocateJSObjectFromMap(initial_map);
   return instance;
 }
 
@@ skipping 377 matching lines @@
   Node* const result = InternalPerformPromiseThen(
       context, promise, on_resolve, on_reject, var_deferred_promise.value(),
       var_deferred_on_resolve.value(), var_deferred_on_reject.value());
   return result;
 }
 
 Node* PromiseBuiltinsAssembler::InternalPerformPromiseThen(
     Node* context, Node* promise, Node* on_resolve, Node* on_reject,
     Node* deferred_promise, Node* deferred_on_resolve,
     Node* deferred_on_reject) {
-
   Variable var_on_resolve(this, MachineRepresentation::kTagged),
       var_on_reject(this, MachineRepresentation::kTagged);
 
   var_on_resolve.Bind(on_resolve);
   var_on_reject.Bind(on_reject);
 
   Label out(this), if_onresolvenotcallable(this), onrejectcheck(this),
       append_callbacks(this);
   GotoIf(TaggedIsSmi(on_resolve), &if_onresolvenotcallable);
 
@@ skipping 1329 matching lines @@
     // 5. Return ?  Invoke(promise, "then", « thenFinally, catchFinally »).
     Node* const result =
         CallJS(call_callable, context, then, promise, var_then_finally.value(),
                var_catch_finally.value());
     Return(result);
   }
 }
 
 }  // namespace internal
 }  // namespace v8