Remove special debug ExternalReferences.

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 324 matching lines @@
   bool break_on_uncaught_exception() {
     return break_on_uncaught_exception_;
   }
 
   enum AddressId {
     k_after_break_target_address,
     k_restarter_frame_function_pointer
   };
 
   // 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 after_break_target_address() {
+    return reinterpret_cast<Address>(&thread_local_.after_break_target_);
   }
-  Address* restarter_frame_function_pointer_address() {
+
+  Address restarter_frame_function_pointer_address() {
     Object*** address = &thread_local_.restarter_frame_function_pointer_;
-    return reinterpret_cast<Address*>(address);
+    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;
 
@@ skipping 550 matching lines @@
     isolate_->debug()->set_disable_break(prev_disable_break_);
   }
 
  private:
   Isolate* isolate_;
   // The previous state of the disable break used to restore the value when this
   // object is destructed.
   bool prev_disable_break_;
 };
 
-
-// Debug_Address encapsulates the Address pointers used in generating debug
-// code.
-class Debug_Address {
- public:
-  explicit Debug_Address(Debug::AddressId id) : id_(id) { }
-
-  static Debug_Address AfterBreakTarget() {
-    return Debug_Address(Debug::k_after_break_target_address);
-  }
-
-  static Debug_Address RestarterFrameFunctionPointer() {
-    return Debug_Address(Debug::k_restarter_frame_function_pointer);
-  }
-
-  Address address(Isolate* isolate) const {
-    Debug* debug = isolate->debug();
-    switch (id_) {
-      case Debug::k_after_break_target_address:
-        return reinterpret_cast<Address>(debug->after_break_target_address());
-      case Debug::k_restarter_frame_function_pointer:
-        return reinterpret_cast<Address>(
-            debug->restarter_frame_function_pointer_address());
-      default:
-        UNREACHABLE();
-        return NULL;
-    }
-  }
-
- private:
-  Debug::AddressId id_;
-};
-
 } }  // namespace v8::internal
 
 #endif  // V8_DEBUG_H_