[cleanup] Delete MacroAssembler::CopyBytes, it is dead code

src/s390/macro-assembler-s390.h

 // 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.
 
 #ifndef V8_S390_MACRO_ASSEMBLER_S390_H_
 #define V8_S390_MACRO_ASSEMBLER_S390_H_
 
 #include "src/assembler.h"
 #include "src/bailout-reason.h"
 #include "src/frames.h"
@@ skipping 1014 matching lines @@
                                    Register scratch1, Register scratch2,
                                    Register heap_number_map,
                                    Label* gc_required);
 
   // Allocate and initialize a JSValue wrapper with the specified {constructor}
   // and {value}.
   void AllocateJSValue(Register result, Register constructor, Register value,
                        Register scratch1, Register scratch2,
                        Label* gc_required);
 
-  // Copies a number of bytes from src to dst. All registers are clobbered. On
-  // exit src and dst will point to the place just after where the last byte was
-  // read or written and length will be zero.
-  void CopyBytes(Register src, Register dst, Register length, Register scratch);
-
   // Initialize fields with filler values.  |count| fields starting at
   // |current_address| are overwritten with the value in |filler|.  At the end
   // the loop, |current_address| points at the next uninitialized field.
   // |count| is assumed to be non-zero.
   void InitializeNFieldsWithFiller(Register current_address, Register count,
                                    Register filler);
 
   // Initialize fields with filler values.  Fields starting at |current_address|
   // not including |end_address| are overwritten with the value in |filler|.  At
   // the end the loop, |current_address| takes the value of |end_address|.
@@ skipping 829 matching lines @@
 inline MemOperand NativeContextMemOperand() {
   return ContextMemOperand(cp, Context::NATIVE_CONTEXT_INDEX);
 }
 
 #define ACCESS_MASM(masm) masm->
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_S390_MACRO_ASSEMBLER_S390_H_