Always initialize the debugger eagerly.

src/x64/debug-x64.cc

 // 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.
 
 #include "v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "assembler.h"
 #include "codegen.h"
 #include "debug.h"
 
 
 namespace v8 {
 namespace internal {
 
 bool BreakLocationIterator::IsDebugBreakAtReturn()  {
   return Debug::IsDebugBreakAtReturn(rinfo());
 }
 
 
 // Patch the JS frame exit code with a debug break call. See
 // CodeGenerator::VisitReturnStatement and VirtualFrame::Exit in codegen-x64.cc
 // for the precise return instructions sequence.
 void BreakLocationIterator::SetDebugBreakAtReturn()  {
   ASSERT(Assembler::kJSReturnSequenceLength >= Assembler::kCallSequenceLength);
   rinfo()->PatchCodeWithCall(
-      debug_info_->GetIsolate()->debug()->debug_break_return()->entry(),
+      debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry(),
       Assembler::kJSReturnSequenceLength - Assembler::kCallSequenceLength);
 }
 
 
 // Restore the JS frame exit code.
 void BreakLocationIterator::ClearDebugBreakAtReturn() {
   rinfo()->PatchCode(original_rinfo()->pc(),
                      Assembler::kJSReturnSequenceLength);
 }
 
 
 // A debug break in the frame exit code is identified by the JS frame exit code
 // having been patched with a call instruction.
 bool Debug::IsDebugBreakAtReturn(v8::internal::RelocInfo* rinfo) {
   ASSERT(RelocInfo::IsJSReturn(rinfo->rmode()));
   return rinfo->IsPatchedReturnSequence();
 }
 
 
 bool BreakLocationIterator::IsDebugBreakAtSlot() {
   ASSERT(IsDebugBreakSlot());
   // Check whether the debug break slot instructions have been patched.
   return !Assembler::IsNop(rinfo()->pc());
 }
 
 
 void BreakLocationIterator::SetDebugBreakAtSlot() {
   ASSERT(IsDebugBreakSlot());
   rinfo()->PatchCodeWithCall(
-      debug_info_->GetIsolate()->debug()->debug_break_slot()->entry(),
+      debug_info_->GetIsolate()->builtins()->Slot_DebugBreak()->entry(),
       Assembler::kDebugBreakSlotLength - Assembler::kCallSequenceLength);
 }
 
 
 void BreakLocationIterator::ClearDebugBreakAtSlot() {
   ASSERT(IsDebugBreakSlot());
   rinfo()->PatchCode(original_rinfo()->pc(), Assembler::kDebugBreakSlotLength);
 }
 
 const bool Debug::FramePaddingLayout::kIsSupported = true;
@@ skipping 239 matching lines @@
   __ jmp(rdx);
 }
 
 const bool Debug::kFrameDropperSupported = true;
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64