[builtins] Start refactoring the Apply builtin.

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 1547 matching lines @@
                                Register value2,
                                Label* not_smi_label);
 
   // Abort execution if argument is a smi, enabled via --debug-code.
   void AssertNotSmi(Register object, BailoutReason reason = kOperandIsASmi);
   void AssertSmi(Register object, BailoutReason reason = kOperandIsNotASmi);
 
   inline void ObjectTag(Register tagged_obj, Register obj);
   inline void ObjectUntag(Register untagged_obj, Register obj);
 
+  // Abort execution if argument is not a FixedArray, enabled via --debug-code.
+  void AssertFixedArray(Register object);
+
   // Abort execution if argument is not a JSFunction, enabled via --debug-code.
   void AssertFunction(Register object);
 
   // Abort execution if argument is not a JSGeneratorObject,
   // enabled via --debug-code.
   void AssertGeneratorObject(Register object, Register suspend_flags);
 
   // Abort execution if argument is not a JSBoundFunction,
   // enabled via --debug-code.
   void AssertBoundFunction(Register object);
@@ skipping 1119 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_