[turbofan] Add NewUnmappedArgumentsElements and NewRestParametersArguments.

src/runtime/runtime-scopes.cc

 // Copyright 2014 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/runtime/runtime-utils.h"
 
 #include <memory>
 
 #include "src/accessors.h"
 #include "src/arguments.h"
@@ skipping 574 matching lines @@
 RUNTIME_FUNCTION(Runtime_NewSloppyArguments) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 3);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, callee, 0);
   Object** parameters = reinterpret_cast<Object**>(args[1]);
   CONVERT_SMI_ARG_CHECKED(argument_count, 2);
   ParameterArguments argument_getter(parameters);
   return *NewSloppyArguments(isolate, callee, argument_getter, argument_count);
 }
 
+RUNTIME_FUNCTION(Runtime_NewArgumentsElements) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+  Object** frame = reinterpret_cast<Object**>(args[0]);
+  CONVERT_SMI_ARG_CHECKED(length, 1);
+  Handle<FixedArray> result =
+      isolate->factory()->NewUninitializedFixedArray(length);
+  int const offset = length + 1;
+  DisallowHeapAllocation no_gc;
+  WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc);
+  for (int index = 0; index < length; ++index) {
+    result->set(index, frame[offset - index], mode);
+  }
+  return *result;
+}
 
 RUNTIME_FUNCTION(Runtime_NewClosure) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(SharedFunctionInfo, shared, 0);
   Handle<Context> context(isolate->context(), isolate);
   return *isolate->factory()->NewFunctionFromSharedFunctionInfo(shared, context,
                                                                 NOT_TENURED);
 }
 
@@ skipping 354 matching lines @@
 RUNTIME_FUNCTION(Runtime_StoreLookupSlot_Strict) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(String, name, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, value, 1);
   RETURN_RESULT_OR_FAILURE(isolate, StoreLookupSlot(name, value, STRICT));
 }
 
 }  // namespace internal
 }  // namespace v8