Add Process.runSync for running processe synchronously.

runtime/bin/io_buffer.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/io_buffer.h"
 
 
 namespace dart {
 namespace bin {
 
 Dart_Handle IOBuffer::Allocate(intptr_t size, uint8_t **buffer) {
   uint8_t* data = Allocate(size);
   Dart_Handle result = Dart_NewExternalTypedData(
       Dart_TypedData_kUint8, data, size);
   Dart_NewWeakPersistentHandle(result, data, IOBuffer::Finalizer);
 
   if (Dart_IsError(result)) {
     Free(data);
     Dart_PropagateError(result);
   }
   if (buffer != NULL) {
     *buffer = data;
   }
   return result;
 }
 
+
 uint8_t* IOBuffer::Allocate(intptr_t size) {
   return new uint8_t[size];
 }
 
 }  // namespace bin
 }  // namespace dart