Always include debugger support.

src/arm64/debug-arm64.cc

 // Copyright 2013 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 20 matching lines @@
 
 #include "codegen.h"
 #include "debug.h"
 
 namespace v8 {
 namespace internal {
 
 
 #define __ ACCESS_MASM(masm)
 
-
-#ifdef ENABLE_DEBUGGER_SUPPORT
 bool BreakLocationIterator::IsDebugBreakAtReturn() {
   return Debug::IsDebugBreakAtReturn(rinfo());
 }
 
 
 void BreakLocationIterator::SetDebugBreakAtReturn() {
   // Patch the code emitted by FullCodeGenerator::EmitReturnSequence, changing
   // the return from JS function sequence from
   //   mov sp, fp
   //   ldp fp, lr, [sp] #16
@@ skipping 326 matching lines @@
   masm->Abort(kLiveEditFrameDroppingIsNotSupportedOnARM64);
 }
 
 
 void Debug::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
   masm->Abort(kLiveEditFrameDroppingIsNotSupportedOnARM64);
 }
 
 const bool Debug::kFrameDropperSupported = false;
 
-#endif  // ENABLE_DEBUGGER_SUPPORT
-
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64