Remove unused thread locals from debugger.

src/debug.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_DEBUG_H_
 #define V8_DEBUG_H_
 
 #include "allocation.h"
 #include "arguments.h"
 #include "assembler.h"
@@ skipping 332 matching lines @@
 
   // Support for setting the address to jump to when returning from break point.
   Address* after_break_target_address() {
     return reinterpret_cast<Address*>(&thread_local_.after_break_target_);
   }
   Address* restarter_frame_function_pointer_address() {
     Object*** address = &thread_local_.restarter_frame_function_pointer_;
     return reinterpret_cast<Address*>(address);
   }
 
-  // Support for saving/restoring registers when handling debug break calls.
-  Object** register_address(int r) {
-    return &registers_[r];
-  }
-
   static const int kEstimatedNofDebugInfoEntries = 16;
   static const int kEstimatedNofBreakPointsInFunction = 16;
 
   // Passed to MakeWeak.
   static void HandleWeakDebugInfo(
       const v8::WeakCallbackData<v8::Value, void>& data);
 
   friend class Debugger;
   friend Handle<FixedArray> GetDebuggedFunctions();  // In test-debug.cc
   friend void CheckDebuggerUnloaded(bool check_functions);  // In test-debug.cc
@@ skipping 211 matching lines @@
     // Pending interrupts scheduled while debugging.
     bool has_pending_interrupt_;
 
     // When restarter frame is on stack, stores the address
     // of the pointer to function being restarted. Otherwise (most of the time)
     // stores NULL. This pointer is used with 'step in' implementation.
     Object** restarter_frame_function_pointer_;
   };
 
   // Storage location for registers when handling debug break calls
-  JSCallerSavedBuffer registers_;
   ThreadLocal thread_local_;
   void ThreadInit();
 
   Isolate* isolate_;
 
   friend class Isolate;
 
   DISALLOW_COPY_AND_ASSIGN(Debug);
 };
 
@@ skipping 347 matching lines @@
     }
   }
 
  private:
   Debug::AddressId id_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_DEBUG_H_