A64: Use a scope utility to allocate scratch registers.

src/a64/debug-a64.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 157 matching lines @@
     //
     //  * non_object_regs will be converted to SMIs so that the garbage
     //    collector doesn't try to interpret them as pointers.
     //
     // TODO(jbramley): Why can't this handle callee-saved registers?
     ASSERT((~kCallerSaved.list() & object_regs) == 0);
     ASSERT((~kCallerSaved.list() & non_object_regs) == 0);
     ASSERT((object_regs & non_object_regs) == 0);
     ASSERT((scratch.Bit() & object_regs) == 0);
     ASSERT((scratch.Bit() & non_object_regs) == 0);
-    ASSERT((ip0.Bit() & (object_regs | non_object_regs)) == 0);
-    ASSERT((ip1.Bit() & (object_regs | non_object_regs)) == 0);
+    ASSERT((masm->TmpList()->list() & (object_regs | non_object_regs)) == 0);
     STATIC_ASSERT(kSmiValueSize == 32);
 
     CPURegList non_object_list =
         CPURegList(CPURegister::kRegister, kXRegSize, non_object_regs);
     while (!non_object_list.IsEmpty()) {
       // Store each non-object register as two SMIs.
       Register reg = Register(non_object_list.PopLowestIndex());
       __ Push(reg);
       __ Poke(wzr, 0);
       __ Push(reg.W(), wzr);
@@ skipping 195 matching lines @@
   masm->Abort(kLiveEditFrameDroppingIsNotSupportedOnA64);
 }
 
 const bool Debug::kFrameDropperSupported = false;
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_A64