Backport ff0a97933 from V8

Node.js 10.2.0 needs it.

https://chromium-review.googlesource.com/1057467
nodejs/node#20409

patches/common/v8/.patches.yaml

@@ -34,3 +34,7 @@ patches:
   owners: alexeykuzmin
   file: backport_39d546a.patch
   description: Node 10.0.0 needs it.
+-
+  owners: alexeykuzmin
+  file: backport_ff0a97933.patch
+  description: Node 10.2.0 needs it.

patches/common/v8/backport_ff0a97933.patch

@@ -0,0 +1,89 @@
+ff0a979333408f544f081489411814b84df6e2d9
+diff --git a/include/v8.h b/include/v8.h
+index 07ee083695..a09932383f 100644
+--- a/include/v8.h
++++ b/include/v8.h
+@@ -3493,6 +3498,17 @@ class V8_EXPORT Object : public Value {
+    */
+   V8_DEPRECATE_SOON("Keep track of isolate correctly", Isolate* GetIsolate());
+
++  /**
++   * If this object is a Set, Map, WeakSet or WeakMap, this returns a
++   * representation of the elements of this object as an array.
++   * If this object is a SetIterator or MapIterator, this returns all
++   * elements of the underlying collection, starting at the iterator's current
++   * position.
++   * For other types, this will return an empty MaybeLocal<Array> (without
++   * scheduling an exception).
++   */
++  MaybeLocal<Array> PreviewEntries(bool* is_key_value);
++
+   static Local<Object> New(Isolate* isolate);
+
+   V8_INLINE static Object* Cast(Value* obj);
+diff --git a/src/api.cc b/src/api.cc
+index e65f114edb..4302b6c604 100644
+--- a/src/api.cc
++++ b/src/api.cc
+@@ -9543,21 +9543,20 @@ int debug::EstimatedValueSize(Isolate* v8_isolate, v8::Local<v8::Value> value) {
+   return i::Handle<i::HeapObject>::cast(object)->Size();
+ }
+
+-v8::MaybeLocal<v8::Array> debug::EntriesPreview(Isolate* v8_isolate,
+-                                                v8::Local<v8::Value> value,
+-                                                bool* is_key_value) {
+-  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+-  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(isolate);
+-  if (value->IsMap()) {
++v8::MaybeLocal<v8::Array> v8::Object::PreviewEntries(bool* is_key_value) {
++  if (IsMap()) {
+     *is_key_value = true;
+-    return value.As<Map>()->AsArray();
++    return Map::Cast(this)->AsArray();
+   }
+-  if (value->IsSet()) {
++  if (IsSet()) {
+     *is_key_value = false;
+-    return value.As<Set>()->AsArray();
++    return Set::Cast(this)->AsArray();
+   }
+
+-  i::Handle<i::Object> object = Utils::OpenHandle(*value);
++  i::Handle<i::JSReceiver> object = Utils::OpenHandle(this);
++  i::Isolate* isolate = object->GetIsolate();
++  Isolate* v8_isolate = reinterpret_cast<Isolate*>(isolate);
++  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(isolate);
+   if (object->IsJSWeakCollection()) {
+     *is_key_value = object->IsJSWeakMap();
+     return Utils::ToLocal(i::JSWeakCollection::GetEntries(
+diff --git a/src/debug/debug-interface.h b/src/debug/debug-interface.h
+index 01124bf7fc..2210b4e87f 100644
+--- a/src/debug/debug-interface.h
++++ b/src/debug/debug-interface.h
+@@ -212,10 +212,6 @@ void ResetBlackboxedStateCache(Isolate* isolate,
+
+ int EstimatedValueSize(Isolate* isolate, v8::Local<v8::Value> value);
+
+-v8::MaybeLocal<v8::Array> EntriesPreview(Isolate* isolate,
+-                                         v8::Local<v8::Value> value,
+-                                         bool* is_key_value);
+-
+ enum Builtin {
+   kObjectKeys,
+   kObjectGetPrototypeOf,
+diff --git a/src/inspector/v8-debugger.cc b/src/inspector/v8-debugger.cc
+index 5dee98853b..28212a1993 100644
+--- a/src/inspector/v8-debugger.cc
++++ b/src/inspector/v8-debugger.cc
+@@ -29,8 +29,10 @@ v8::MaybeLocal<v8::Array> collectionsEntries(v8::Local<v8::Context> context,
+   v8::Isolate* isolate = context->GetIsolate();
+   v8::Local<v8::Array> entries;
+   bool isKeyValue = false;
+-  if (!v8::debug::EntriesPreview(isolate, value, &isKeyValue).ToLocal(&entries))
++  if (!value->IsObject() ||
++      !value.As<v8::Object>()->PreviewEntries(&isKeyValue).ToLocal(&entries)) {
+     return v8::MaybeLocal<v8::Array>();
++  }
+
+   v8::Local<v8::Array> wrappedEntries = v8::Array::New(isolate);
+   CHECK(!isKeyValue || wrappedEntries->Length() % 2 == 0);