deps: provide v8 backwards compatibility from upstream

Fix nwjs/nw.js#6869

Author: rogerwang

include/v8.h

@@ -2987,6 +2987,8 @@ class V8_EXPORT String : public Name {
    */
   class V8_EXPORT Utf8Value {
    public:
+    V8_DEPRECATED("Use Isolate version",
+                  explicit Utf8Value(Local<v8::Value> obj));
     Utf8Value(Isolate* isolate, Local<v8::Value> obj);
     ~Utf8Value();
     char* operator*() { return str_; }
@@ -3010,6 +3012,7 @@ class V8_EXPORT String : public Name {
    */
   class V8_EXPORT Value {
    public:
+    V8_DEPRECATED("Use Isolate version", explicit Value(Local<v8::Value> obj));
     Value(Isolate* isolate, Local<v8::Value> obj);
     ~Value();
     uint16_t* operator*() { return str_; }

src/api.cc

@@ -3933,7 +3933,6 @@ void v8::RegExp::CheckCast(v8::Value* that) {
                   "Could not convert to regular expression");
 }
 
-
 Maybe<bool> Value::BooleanValue(Local<Context> context) const {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(context->GetIsolate());
   return Just(Utils::OpenHandle(this)->BooleanValue(isolate));
@@ -5629,6 +5628,7 @@ static bool RecursivelySerializeToUtf8(i::String* current,
   return true;
 }
 
+
 int String::WriteUtf8(Isolate* v8_isolate, char* buffer, int capacity,
                       int* nchars_ref, int options) const {
   i::Handle<i::String> str = Utils::OpenHandle(this);
@@ -9062,6 +9062,9 @@ bool MicrotasksScope::IsRunningMicrotasks(Isolate* v8Isolate) {
   return isolate->IsRunningMicrotasks();
 }
 
+String::Utf8Value::Utf8Value(v8::Local<v8::Value> obj)
+  : Utf8Value(Isolate::GetCurrent(), obj) {}
+
 String::Utf8Value::Utf8Value(v8::Isolate* isolate, v8::Local<v8::Value> obj)
     : str_(nullptr), length_(0) {
   if (obj.IsEmpty()) return;
@@ -9081,6 +9084,9 @@ String::Utf8Value::~Utf8Value() {
   i::DeleteArray(str_);
 }
 
+String::Value::Value(v8::Local<v8::Value> obj)
+  : Value(Isolate::GetCurrent(), obj) {}
+
 String::Value::Value(v8::Isolate* isolate, v8::Local<v8::Value> obj)
     : str_(nullptr), length_(0) {
   if (obj.IsEmpty()) return;