Fixed broken build of mksnapshot on Windows as there was warnings against...

src/mksnapshot.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 98 matching lines @@
   counter_table_[counter] = ptr;
   return ptr;
 }
 
 
 // Write C++ code that defines Snapshot::snapshot_ to contain the snapshot
 // to the file given by filename. Only the first size chars are written.
 static int WriteInternalSnapshotToFile(const char* filename,
                                        const char* str,
                                        int size) {
-  FILE* f = fopen(filename, "wb");
+  FILE* f = i::OS::FOpen(filename, "wb");
   if (f == NULL) {
     i::OS::PrintError("Cannot open file %s for reading.\n", filename);
     return 0;
   }
   fprintf(f, "// Autogenerated snapshot file. Do not edit.\n\n");
   fprintf(f, "#include \"v8.h\"\n");
   fprintf(f, "#include \"platform.h\"\n\n");
   fprintf(f, "#include \"snapshot.h\"\n\n");
   fprintf(f, "namespace v8 {\nnamespace internal {\n\n");
   fprintf(f, "const char Snapshot::data_[] = {");
@@ skipping 51 matching lines @@
   char* str;
   int len;
   ser.Finalize(&str, &len);
 
   WriteInternalSnapshotToFile(argv[1], str, len);
 
   i::DeleteArray(str);
 
   return 0;
 }