Remove special debug ExternalReferences.

test/cctest/test-disasm-x64.cc

 // Copyright 2011 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 243 matching lines @@
   __ nop();
   Handle<Code> ic(LoadIC::initialize_stub(isolate, NOT_CONTEXTUAL));
   __ call(ic, RelocInfo::CODE_TARGET);
   __ nop();
   __ nop();
 
   __ jmp(&L1);
   // TODO(mstarzinger): The following is protected.
   // __ jmp(Operand(rbx, rcx, times_4, 10000));
   ExternalReference after_break_target =
-      ExternalReference(Debug_Address::AfterBreakTarget(), isolate);
+      ExternalReference::debug_after_break_target_address(isolate);
   USE(after_break_target);
   __ jmp(ic, RelocInfo::CODE_TARGET);
   __ nop();
 
 
   Label Ljcc;
   __ nop();
   // long jumps
   __ j(overflow, &Ljcc);
   __ j(no_overflow, &Ljcc);
@@ skipping 159 matching lines @@
   USE(code);
 #ifdef OBJECT_PRINT
   code->Print();
   byte* begin = code->instruction_start();
   byte* end = begin + code->instruction_size();
   disasm::Disassembler::Disassemble(stdout, begin, end);
 #endif
 }
 
 #undef __