Restore performance of accesses to JSGlobalProxy after r22802

src/ic.cc

Index: src/ic.cc
diff --git a/src/ic.cc b/src/ic.cc
index bbfb2dd781283d5d03b43d3710401fa0e8779d05..a41366daf1e0dac081aba55d7fb8dc5e11e16e9b 100644
--- a/src/ic.cc
+++ b/src/ic.cc
@@ -211,6 +211,12 @@ static void LookupForRead(LookupIterator* it) {
         break;
       }
       case LookupIterator::ACCESS_CHECK:
+        // PropertyHandlerCompiler::CheckPrototypes() knows how to emit
+        // access checks for global proxies.
+        if (it->GetHolder<JSObject>()->IsJSGlobalProxy() &&
+            it->HasAccess(v8::ACCESS_GET)) {
+          break;
+        }
         return;
       case LookupIterator::PROPERTY:
         if (it->HasProperty()) return;  // Yay!