Fix leak from new/free mismatch in main.

runtime/bin/main.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 <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
 #include "include/dart_api.h"
 #include "include/dart_debugger_api.h"
@@ skipping 1136 matching lines @@
   }
 
   // Free environment if any.
   if (environment != NULL) {
     for (HashMap::Entry* p = environment->Start();
          p != NULL;
          p = environment->Next(p)) {
       free(p->key);
       free(p->value);
     }
-    free(environment);
+    delete environment;
   }
 
   exit(Process::GlobalExitCode());
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   dart::bin::main(argc, argv);
   UNREACHABLE();
 }