Fixed issue in MallocHooks where a MallocHookScope was accidentally removed during a merge, causing…

runtime/vm/os_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 "vm/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "vm/os.h"
 
 #include <malloc.h>   // NOLINT
@@ skipping 247 matching lines @@
   __builtin_trap();
 #else
   // Microsoft style assembly.
   __asm {
     int 3
   }
 #endif
 }
 
 
+DART_NOINLINE uintptr_t OS::GetProgramCounter() {
+  return reinterpret_cast<uintptr_t>(_ReturnAddress());
+}
+
+
 char* OS::StrNDup(const char* s, intptr_t n) {
   intptr_t len = strlen(s);
   if ((n < 0) || (len < 0)) {
     return NULL;
   }
   if (n < len) {
     len = n;
   }
   char* result = reinterpret_cast<char*>(malloc(len + 1));
   if (result == NULL) {
@@ skipping 167 matching lines @@
   // TODO(zra): Remove once VM shuts down cleanly.
   private_flag_windows_run_tls_destructors = false;
   // On Windows we use ExitProcess so that threads can't clobber the exit_code.
   // See: https://code.google.com/p/nativeclient/issues/detail?id=2870
   ::ExitProcess(code);
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)