Move assert.h/assert.cc from runtime/vm to runtime/platform

runtime/vm/utils.h

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
 #ifndef VM_UTILS_H_
 #define VM_UTILS_H_
 
-#include "vm/assert.h"
+#include "platform/assert.h"
+#include "vm/globals.h"
 
 namespace dart {
 
 class Utils {
  public:
   template<typename T>
   static inline T Minimum(T x, T y) {
     return x < y ? x : y;
   }
 
@@ skipping 126 matching lines @@
   static char IntToHexDigit(int i) {
     ASSERT(0 <= i && i < 16);
     if (i < 10) return static_cast<char>('0' + i);
     return static_cast<char>('A' + (i - 10));
   }
 };
 
 }  // namespace dart
 
 #endif  // VM_UTILS_H_