Get rid of duplicated CPU::DebugBreak() method.

src/mips/cpu-mips.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 69 matching lines @@
 #else  // USE_SIMULATOR.
   // Not generating mips instructions for C-code. This means that we are
   // building a mips emulator based target.  We should notify the simulator
   // that the Icache was flushed.
   // None of this code ends up in the snapshot so there are no issues
   // around whether or not to generate the code when building snapshots.
   Simulator::FlushICache(Isolate::Current()->simulator_i_cache(), start, size);
 #endif  // USE_SIMULATOR.
 }
 
-
-void CPU::DebugBreak() {
-#ifdef __mips
-  asm volatile("break");
-#endif  // #ifdef __mips
-}
-
-
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS