Fix trivial error when building with clang.

src/d8.cc

 // Copyright 2012 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 150 matching lines @@
 i::Mutex Shell::context_mutex_;
 const i::TimeTicks Shell::kInitialTicks = i::TimeTicks::HighResolutionNow();
 Persistent<Context> Shell::utility_context_;
 #endif  // V8_SHARED
 
 Persistent<Context> Shell::evaluation_context_;
 ShellOptions Shell::options;
 const char* Shell::kPrompt = "d8> ";
 
 
+#ifndef V8_SHARED
 const int MB = 1024 * 1024;
 
-
-#ifndef V8_SHARED
 bool CounterMap::Match(void* key1, void* key2) {
   const char* name1 = reinterpret_cast<const char*>(key1);
   const char* name2 = reinterpret_cast<const char*>(key2);
   return strcmp(name1, name2) == 0;
 }
 #endif  // V8_SHARED
 
 
 // Converts a V8 value to a C string.
 const char* Shell::ToCString(const v8::String::Utf8Value& value) {
@@ skipping 1578 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif