Always include debugger support.

src/x64/macro-assembler-x64.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 3674 matching lines @@
     Operand counter_operand = ExternalOperand(ExternalReference(counter));
     if (value == 1) {
       decl(counter_operand);
     } else {
       subl(counter_operand, Immediate(value));
     }
   }
 }
 
 
-#ifdef ENABLE_DEBUGGER_SUPPORT
 void MacroAssembler::DebugBreak() {
   Set(rax, 0);  // No arguments.
   LoadAddress(rbx, ExternalReference(Runtime::kDebugBreak, isolate()));
   CEntryStub ces(isolate(), 1);
   ASSERT(AllowThisStubCall(&ces));
   Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
 }
-#endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 void MacroAssembler::InvokeCode(Register code,
                                 const ParameterCount& expected,
                                 const ParameterCount& actual,
                                 InvokeFlag flag,
                                 const CallWrapper& call_wrapper) {
   // You can't call a function without a valid frame.
   ASSERT(flag == JUMP_FUNCTION || has_frame());
 
@@ skipping 1490 matching lines @@
   if (ms.shift() > 0) sarl(rdx, Immediate(ms.shift()));
   movl(rax, dividend);
   shrl(rax, Immediate(31));
   addl(rdx, rax);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64