Re-establish mips basic infrastructure.

src/top.h

 // Copyright 2006-2008 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 98 matching lines @@
   // unify them later.
   MaybeObject* scheduled_exception_;
   bool external_caught_exception_;
   SaveContext* save_context_;
   v8::TryCatch* catcher_;
 
   // Stack.
   Address c_entry_fp_;  // the frame pointer of the top c entry frame
   Address handler_;   // try-blocks are chained through the stack
 
-#ifdef USE_SIMULATOR
-#ifdef V8_TARGET_ARCH_ARM
+#if defined(USE_SIMULATOR) && \
+    (defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_MIPS))
   Simulator* simulator_;
-#elif V8_TARGET_ARCH_MIPS
-  assembler::mips::Simulator* simulator_;
-#endif
 #endif  // USE_SIMULATOR
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
   Address js_entry_sp_;  // the stack pointer of the bottom js entry frame
   Address external_callback_;  // the external callback we're currently in
 #endif
 
 #ifdef ENABLE_VMSTATE_TRACKING
   StateTag current_vm_state_;
 
@@ skipping 464 matching lines @@
   static void Unlock() { Top::break_access_->Unlock(); }
 
   static bool TryLock() {
     return Top::break_access_->TryLock();
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_TOP_H_