Fix race in GC sweeper and isolate reload rollback.

runtime/vm/atomic.h

 // Copyright (c) 2013, 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.
 
 #ifndef VM_ATOMIC_H_
 #define VM_ATOMIC_H_
 
 #include "platform/globals.h"
 
 #include "vm/allocation.h"
@@ skipping 33 matching lines @@
   // Atomically compare *ptr to old_value, and if equal, store new_value.
   // Returns the original value at ptr.
   //
   // NOTE: OK to use with memory locations that are accessed by generated code
   static uword CompareAndSwapWord(uword* ptr, uword old_value, uword new_value);
   static uint32_t CompareAndSwapUint32(
       uint32_t* ptr, uint32_t old_value, uint32_t new_value);
 
   // Performs a load of a word from 'ptr', but without any guarantees about
   // memory order (i.e., no load barriers/fences).
-  static uword LoadRelaxed(uword* ptr) {
-    return *static_cast<volatile uword*>(ptr);
-  }
-
-  // Performs a load of a word from 'ptr', but without any guarantees about
-  // memory order (i.e., no load barriers/fences).
-  static intptr_t LoadRelaxedIntPtr(intptr_t* ptr) {
-    return *static_cast<volatile intptr_t*>(ptr);
+  template <typename T>
+  static T LoadRelaxed(T* ptr) {
+    return *static_cast<volatile T*>(ptr);
   }
 };
 
 
 }  // namespace dart
 
 #if defined(USING_SIMULATOR) && !defined(TARGET_ARCH_DBC)
 #define USING_SIMULATOR_ATOMICS
 #endif
 
@@ skipping 11 matching lines @@
 #include "vm/atomic_linux.h"
 #elif defined(TARGET_OS_MACOS)
 #include "vm/atomic_macos.h"
 #elif defined(TARGET_OS_WINDOWS)
 #include "vm/atomic_win.h"
 #else
 #error Unknown target os.
 #endif
 
 #endif  // VM_ATOMIC_H_