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

src/arm64/macro-assembler-arm64.h

 // 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.
 
 #ifndef V8_ARM64_MACRO_ASSEMBLER_ARM64_H_
 #define V8_ARM64_MACRO_ASSEMBLER_ARM64_H_
 
 #include <vector>
 
 #include "src/arm64/assembler-arm64.h"
@@ skipping 1081 matching lines @@
   }
 
   // ---- Object Utilities ----
 
   // 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|.
   void InitializeFieldsWithFiller(Register current_address,
                                   Register end_address, Register filler);
 
-  // Copies a number of bytes from src to dst. All passed 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. Hint may be used to
-  // determine which is the most efficient algorithm to use for copying.
-  void CopyBytes(Register dst,
-                 Register src,
-                 Register length,
-                 Register scratch,
-                 CopyHint hint = kCopyUnknown);
-
   // ---- String Utilities ----
 
 
   // Jump to label if either object is not a sequential one-byte string.
   // Optionally perform a smi check on the objects first.
   void JumpIfEitherIsNotSequentialOneByteStrings(
       Register first, Register second, Register scratch1, Register scratch2,
       Label* failure, SmiCheckType smi_check = DO_SMI_CHECK);
 
   // Check if instance type is sequential one-byte string and jump to label if
@@ skipping 1167 matching lines @@
   class RegisterBits : public BitField<unsigned, 0, 5> {};
   class DeltaBits : public BitField<uint32_t, 5, 32-5> {};
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #define ACCESS_MASM(masm) masm->
 
 #endif  // V8_ARM64_MACRO_ASSEMBLER_ARM64_H_