Reland "Prevent liveedit on or under generators with open activations"

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 029e80d9bb96e075f39c14c7d9d93566fc5d4321..30bb8a1d1fa9a712796ed57f37ee91d564f8f6ea 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -5718,6 +5718,14 @@ bool JSGeneratorObject::is_suspended() {
   return continuation() > 0;
 }
 
+bool JSGeneratorObject::is_closed() {
+  return continuation() == kGeneratorClosed;
+}
+
+bool JSGeneratorObject::is_executing() {
+  return continuation() == kGeneratorExecuting;
+}
+
 JSGeneratorObject* JSGeneratorObject::cast(Object* obj) {
   ASSERT(obj->IsJSGeneratorObject());
   ASSERT(HeapObject::cast(obj)->Size() == JSGeneratorObject::kSize);