[proxies] Expose proxies in the API

src/objects.cc

 // Copyright 2015 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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 4893 matching lines @@
   if (owned.FromJust() && !target_desc.configurable()) {
     isolate->Throw(*factory->NewTypeError(
         MessageTemplate::kProxyDeletePropertyNonConfigurable, name));
     return Nothing<bool>();
   }
   return Just(true);
 }
 
 
 // static
+MaybeHandle<JSProxy> JSProxy::New(Isolate* isolate, Handle<Object> target,
+                                  Handle<Object> handler) {
+  if (!target->IsJSReceiver()) {
+    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kProxyNonObject),
+                    JSProxy);
+  }
+  if (target->IsJSProxy() && JSProxy::cast(*target)->IsRevoked()) {
+    THROW_NEW_ERROR(isolate,
+                    NewTypeError(MessageTemplate::kProxyHandlerOrTargetRevoked),
+                    JSProxy);
+  }
+  if (!handler->IsJSReceiver()) {
+    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kProxyNonObject),
+                    JSProxy);
+  }
+  if (handler->IsJSProxy() && JSProxy::cast(*handler)->IsRevoked()) {
+    THROW_NEW_ERROR(isolate,
+                    NewTypeError(MessageTemplate::kProxyHandlerOrTargetRevoked),
+                    JSProxy);
+  }
+  return isolate->factory()->NewJSProxy(Handle<JSReceiver>::cast(target),
+                                        Handle<JSReceiver>::cast(handler));
+}
+
+
+// static
 MaybeHandle<Context> JSProxy::GetFunctionRealm(Handle<JSProxy> proxy) {
   DCHECK(proxy->map()->is_constructor());
   if (proxy->IsRevoked()) {
     THROW_NEW_ERROR(proxy->GetIsolate(),
                     NewTypeError(MessageTemplate::kProxyRevoked), Context);
   }
   Handle<JSReceiver> target(JSReceiver::cast(proxy->target()));
   return JSReceiver::GetFunctionRealm(target);
 }
 
@@ skipping 14531 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8