Remove unused IsPromise builtin and is_promise context slot

Change-Id: I2183b08596874d41eece64d6bdecc8f174cd738e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2144547Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67120}

BUILD.gn

@@ -2138,7 +2138,6 @@ v8_source_set("v8_base_without_compiler") {
     "src/builtins/builtins-json.cc",
     "src/builtins/builtins-number.cc",
     "src/builtins/builtins-object.cc",
-    "src/builtins/builtins-promise.cc",
     "src/builtins/builtins-promise.h",
     "src/builtins/builtins-reflect.cc",
     "src/builtins/builtins-regexp.cc",

src/builtins/builtins-definitions.h

@@ -696,9 +696,6 @@ namespace internal {
   TFS(ForInEnumerate, kReceiver)                                               \
   TFS(ForInFilter, kKey, kObject)                                              \
                                                                                \
-  /* Promise */                                                                \
-  CPP(IsPromise)                                                               \
-                                                                               \
   /* Reflect */                                                                \
   ASM(ReflectApply, JSTrampoline)                                              \
   ASM(ReflectConstruct, JSTrampoline)                                          \

src/builtins/builtins-promise.cc

-// Copyright 2017 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-promise.h"
-
-#include "src/builtins/builtins-utils-inl.h"
-#include "src/builtins/builtins.h"
-#include "src/heap/heap-inl.h"  // For ToBoolean. TODO(jkummerow): Drop.
-#include "src/logging/counters.h"
-#include "src/objects/objects-inl.h"
-
-namespace v8 {
-namespace internal {
-
-BUILTIN(IsPromise) {
-  SealHandleScope scope(isolate);
-
-  Handle<Object> object = args.atOrUndefined(isolate, 1);
-  return isolate->heap()->ToBoolean(object->IsJSPromise());
-}
-
-}  // namespace internal
-}  // namespace v8

src/init/bootstrapper.cc

@@ -2441,12 +2441,6 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     Handle<Map> prototype_map(prototype->map(), isolate());
     Map::SetShouldBeFastPrototypeMap(prototype_map, true, isolate_);
 
-    {  // Internal: IsPromise
-      Handle<JSFunction> function = SimpleCreateFunction(
-          isolate_, factory->empty_string(), Builtins::kIsPromise, 1, false);
-      native_context()->set_is_promise(*function);
-    }
-
     {
       Handle<SharedFunctionInfo> info = SimpleCreateSharedFunctionInfo(
           isolate_, Builtins::kPromiseCapabilityDefaultResolve,

src/objects/contexts.h

@@ -54,7 +54,6 @@ enum ContextLookupFlags {
   V(MATH_POW_INDEX, JSFunction, math_pow)                         \
   V(PROMISE_INTERNAL_CONSTRUCTOR_INDEX, JSFunction,               \
     promise_internal_constructor)                                 \
-  V(IS_PROMISE_INDEX, JSFunction, is_promise)                     \
   V(PROMISE_THEN_INDEX, JSFunction, promise_then)
 
 #define NATIVE_CONTEXT_FIELDS(V)                                               \