[turbofan]: Elide extra move when accessing stack or frame register

src/ppc/interface-descriptors-ppc.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.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_PPC
 
 #include "src/interface-descriptors.h"
 
 namespace v8 {
 namespace internal {
 
-const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
-
-
 const Register LoadDescriptor::ReceiverRegister() { return r4; }
 const Register LoadDescriptor::NameRegister() { return r5; }
 const Register LoadDescriptor::SlotRegister() { return r3; }
 
 
 const Register LoadWithVectorDescriptor::VectorRegister() { return r6; }
 
 
 const Register StoreDescriptor::ReceiverRegister() { return r4; }
 const Register StoreDescriptor::NameRegister() { return r5; }
@@ skipping 329 matching lines @@
       r4,  // math rounding function
       r6,  // vector slot id
       r7,  // type vector
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC