Split off remaining runtime functions in runtime.cc.

src/runtime/runtime-strings.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/v8.h"
 
 #include "src/arguments.h"
 #include "src/jsregexp-inl.h"
 #include "src/jsregexp.h"
 #include "src/runtime/runtime.h"
@@ skipping 1238 matching lines @@
 RUNTIME_FUNCTION(RuntimeReference_SubString) {
   SealHandleScope shs(isolate);
   return __RT_impl_Runtime_SubString(args, isolate);
 }
 
 
 RUNTIME_FUNCTION(RuntimeReference_StringAdd) {
   SealHandleScope shs(isolate);
   return __RT_impl_Runtime_StringAdd(args, isolate);
 }
+
+
+RUNTIME_FUNCTION(RuntimeReference_IsStringWrapperSafeForDefaultValueOf) {
+  UNIMPLEMENTED();
+  return NULL;
+}
 }
 }  // namespace v8::internal