Update dart:io to convert strings between UTF8 and current code page

runtime/bin/platform_win.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/platform.h"
 #include "bin/socket.h"
 
-
 bool Platform::Initialize() {
   // Nothing to do on Windows.
   return true;
 }
 
 
 int Platform::NumberOfProcessors() {
   SYSTEM_INFO info;
   GetSystemInfo(&info);
   return info.dwNumberOfProcessors;
@@ skipping 10 matching lines @@
   if (!socket_initialized) {
     // Initialize Socket for gethostname.
     if (!Socket::Initialize()) return false;
     socket_initialized = true;
   }
   return gethostname(buffer, buffer_length) == 0;
 }
 
 
 char** Platform::Environment(intptr_t* count) {
-  char* strings = GetEnvironmentStringsA();
+  char* strings = GetEnvironmentStrings();
   if (strings == NULL) return NULL;
   char* tmp = strings;
   intptr_t i = 0;
   while (*tmp != '\0') {
     i++;
     tmp += (strlen(tmp) + 1);
   }
   *count = i;
   char** result = new char*[i];
+  tmp = strings;
   for (intptr_t current = 0; current < i; current++) {
-    result[current] = strings;
-    strings += (strlen(strings) + 1);
+    result[current] = StringUtils::SystemStringToUtf8(tmp);
+    tmp += (strlen(tmp) + 1);
   }
+  FreeEnvironmentStrings(strings);
   return result;
 }
 
+void Platform::FreeEnvironment(char** env, int count) {
+  for (int i = 0; i < count; i++) free(env[i]);
+  delete[] env;
+}
+
 
 char* Platform::StrError(int error_code) {
   static const int kBufferSize = 1024;
   char* error = static_cast<char*>(malloc(kBufferSize));
   DWORD message_size =
       FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                     NULL,
                     error_code,
                     MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                     error,
                     kBufferSize,
                     NULL);
   if (message_size == 0) {
     if (GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
       fprintf(stderr, "FormatMessage failed %d\n", GetLastError());
     }
     snprintf(error, kBufferSize, "OS Error %d", error_code);
   }
   // Strip out \r\n at the end of the generated message and ensure
   // null termination.
   if (message_size > 2 &&
       error[message_size - 2] == '\r' &&
       error[message_size - 1] == '\n') {
     error[message_size - 2] = '\0';
   } else {
     error[kBufferSize - 1] = '\0';
   }
   return error;
 }