Always initialize the debugger eagerly.

src/arm64/debug-arm64.cc

 // Copyright 2013 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_ARM64
 
 #include "codegen.h"
 #include "debug.h"
@@ skipping 24 matching lines @@
   //   blr ip0
   //   hlt kHltBadCode    @ code should not return, catch if it does.
   //   <debug break return code ...
   //    ... entry point address (64 bits)>
 
   // The patching code must not overflow the space occupied by the return
   // sequence.
   STATIC_ASSERT(Assembler::kJSRetSequenceInstructions >= 5);
   PatchingAssembler patcher(reinterpret_cast<Instruction*>(rinfo()->pc()), 5);
   byte* entry =
-      debug_info_->GetIsolate()->debug()->debug_break_return()->entry();
+      debug_info_->GetIsolate()->builtins()->Return_DebugBreak()->entry(),
 
   // The first instruction of a patched return sequence must be a load literal
   // loading the address of the debug break return code.
   patcher.LoadLiteral(ip0, 3 * kInstructionSize);
   // TODO(all): check the following is correct.
   // The debug break return code will push a frame and call statically compiled
   // code. By using blr, even though control will not return after the branch,
   // this call site will be registered in the frame (lr being saved as the pc
   // of the next instruction to execute for this frame). The debugger can now
   // iterate on the frames to find call to debug break return code.
@@ skipping 38 matching lines @@
 
   // TODO(all): consider adding a hlt instruction after the blr as we don't
   // expect control to return here. This implies increasing
   // kDebugBreakSlotInstructions to 5 instructions.
 
   // The patching code must not overflow the space occupied by the return
   // sequence.
   STATIC_ASSERT(Assembler::kDebugBreakSlotInstructions >= 4);
   PatchingAssembler patcher(reinterpret_cast<Instruction*>(rinfo()->pc()), 4);
   byte* entry =
-      debug_info_->GetIsolate()->debug()->debug_break_slot()->entry();
+      debug_info_->GetIsolate()->builtins()->Slot_DebugBreak()->entry();
 
   // The first instruction of a patched debug break slot must be a load literal
   // loading the address of the debug break slot code.
   patcher.LoadLiteral(ip0, 2 * kInstructionSize);
   // TODO(all): check the following is correct.
   // The debug break slot code will push a frame and call statically compiled
   // code. By using blr, event hough control will not return after the branch,
   // this call site will be registered in the frame (lr being saved as the pc
   // of the next instruction to execute for this frame). The debugger can now
   // iterate on the frames to find call to debug break slot code.
@@ skipping 232 matching lines @@
 
 void Debug::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
   masm->Abort(kLiveEditFrameDroppingIsNotSupportedOnARM64);
 }
 
 const bool Debug::kFrameDropperSupported = false;
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64