Fix missing cases of empty_string canonicalization

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 1985 matching lines @@
   // This handle will be patched with the code object on installation.
   Handle<Object> code_object_;
 
   // The register to use as a stack pointer for stack operations.
   Register sp_;
 
   // Scratch registers available for use by the MacroAssembler.
   CPURegList tmp_list_;
   CPURegList fptmp_list_;
 
-  void InitializeNewString(Register string,
-                           Register length,
-                           Heap::RootListIndex map_index,
-                           Register scratch1,
-                           Register scratch2);
-
  public:
   // Far branches resolving.
   //
   // The various classes of branch instructions with immediate offsets have
   // different ranges. While the Assembler will fail to assemble a branch
   // exceeding its range, the MacroAssembler offers a mechanism to resolve
   // branches to too distant targets, either by tweaking the generated code to
   // use branch instructions with wider ranges or generating veneers.
   //
   // Currently branches to distant targets are resolved using unconditional
@@ skipping 166 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_