Remove strong mode support from rest argument creation.

src/runtime/runtime-scopes.cc

Index: src/runtime/runtime-scopes.cc
diff --git a/src/runtime/runtime-scopes.cc b/src/runtime/runtime-scopes.cc
index a56ca21da4ca85a6d9a8f5dca3e1ec74da7977c0..c21f4bae596ae9d4948ffc089fb2baf76196e7b7 100644
--- a/src/runtime/runtime-scopes.cc
+++ b/src/runtime/runtime-scopes.cc
@@ -642,8 +642,7 @@ RUNTIME_FUNCTION(Runtime_NewStrictArguments) {
 
 
 static Handle<JSArray> NewRestParam(Isolate* isolate, Object** parameters,
-                                    int num_params, int rest_index,
-                                    LanguageMode language_mode) {
+                                    int num_params, int rest_index) {
   parameters -= rest_index;
   int num_elements = std::max(0, num_params - rest_index);
   Handle<FixedArray> elements =
@@ -651,29 +650,26 @@ static Handle<JSArray> NewRestParam(Isolate* isolate, Object** parameters,
   for (int i = 0; i < num_elements; ++i) {
     elements->set(i, *--parameters);
   }
-  return isolate->factory()->NewJSArrayWithElements(
-      elements, FAST_ELEMENTS, num_elements, strength(language_mode));
+  return isolate->factory()->NewJSArrayWithElements(elements, FAST_ELEMENTS,
+                                                    num_elements);
 }
 
 
 RUNTIME_FUNCTION(Runtime_NewRestParam) {
   HandleScope scope(isolate);
-  DCHECK(args.length() == 4);
+  DCHECK(args.length() == 3);
   CONVERT_SMI_ARG_CHECKED(num_params, 0);
   Object** parameters = reinterpret_cast<Object**>(args[1]);
   CONVERT_SMI_ARG_CHECKED(rest_index, 2);
-  CONVERT_SMI_ARG_CHECKED(language_mode, 3);
 
-  return *NewRestParam(isolate, parameters, num_params, rest_index,
-                       static_cast<LanguageMode>(language_mode));
+  return *NewRestParam(isolate, parameters, num_params, rest_index);
 }
 
 
 RUNTIME_FUNCTION(Runtime_NewRestParamSlow) {
   HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
+  DCHECK(args.length() == 1);
   CONVERT_SMI_ARG_CHECKED(rest_index, 0);
-  CONVERT_SMI_ARG_CHECKED(language_mode, 1);
 
   JavaScriptFrameIterator it(isolate);
 
@@ -684,8 +680,7 @@ RUNTIME_FUNCTION(Runtime_NewRestParamSlow) {
   int argument_count = frame->GetArgumentsLength();
   Object** parameters = reinterpret_cast<Object**>(frame->GetParameterSlot(-1));
 
-  return *NewRestParam(isolate, parameters, argument_count, rest_index,
-                       static_cast<LanguageMode>(language_mode));
+  return *NewRestParam(isolate, parameters, argument_count, rest_index);
 }