Split more runtime functions into seperate files.

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 1164 matching lines @@
   // This is slightly convoluted because the value that signifies
   // equality is 0 and inequality is 1 so we have to negate the result
   // from String::Equals.
   DCHECK(not_equal == 0 || not_equal == 1);
   STATIC_ASSERT(EQUAL == 0);
   STATIC_ASSERT(NOT_EQUAL == 1);
   return Smi::FromInt(not_equal);
 }
 
 
+RUNTIME_FUNCTION(Runtime_FlattenString) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(String, str, 0);
+  return *String::Flatten(str);
+}
+
+
 RUNTIME_FUNCTION(RuntimeReference_StringCharFromCode) {
   SealHandleScope shs(isolate);
   return __RT_impl_Runtime_CharFromCode(args, isolate);
 }
 
 
 RUNTIME_FUNCTION(RuntimeReference_StringCharAt) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 2);
   if (!args[0]->IsString()) return Smi::FromInt(0);
@@ skipping 48 matching lines @@
   return __RT_impl_Runtime_SubString(args, isolate);
 }
 
 
 RUNTIME_FUNCTION(RuntimeReference_StringAdd) {
   SealHandleScope shs(isolate);
   return __RT_impl_Runtime_StringAdd(args, isolate);
 }
 }
 }  // namespace v8::internal