[cleanup] Drop unused scratch register from {load,store}_calling_convention

src/ic/arm64/access-compiler-arm64.cc

 // Copyright 2014 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.
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/ic/access-compiler.h"
 
 namespace v8 {
 namespace internal {
 
 #define __ ACCESS_MASM(masm)
 
 
 void PropertyAccessCompiler::GenerateTailCall(MacroAssembler* masm,
                                               Handle<Code> code) {
   __ Jump(code, RelocInfo::CODE_TARGET);
 }
 
 
 // TODO(all): The so-called scratch registers are significant in some cases. For
 // example, PropertyAccessCompiler::keyed_store_calling_convention()[3] (x3) is
 // actually
 // used for KeyedStoreCompiler::transition_map(). We should verify which
 // registers are actually scratch registers, and which are important. For now,
 // we use the same assignments as ARM to remain on the safe side.
 
 Register* PropertyAccessCompiler::load_calling_convention() {
-  // receiver, name, scratch1, scratch2, scratch3, scratch4.
+  // receiver, name, scratch1, scratch2, scratch3.
   Register receiver = LoadDescriptor::ReceiverRegister();
   Register name = LoadDescriptor::NameRegister();
-  static Register registers[] = {receiver, name, x3, x0, x4, x5};
+  static Register registers[] = {receiver, name, x3, x0, x4};
   return registers;
 }
 
 
 Register* PropertyAccessCompiler::store_calling_convention() {
-  // receiver, value, scratch1, scratch2, scratch3.
+  // receiver, value, scratch1, scratch2.
   Register receiver = StoreDescriptor::ReceiverRegister();
   Register name = StoreDescriptor::NameRegister();
-  static Register registers[] = {receiver, name, x3, x4, x5};
+  static Register registers[] = {receiver, name, x3, x4};
   return registers;
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64