[builtins] Start refactoring the Apply builtin.

src/x64/macro-assembler-x64.h

 // Copyright 2012 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_X64_MACRO_ASSEMBLER_X64_H_
 #define V8_X64_MACRO_ASSEMBLER_X64_H_
 
 #include "src/bailout-reason.h"
 #include "src/base/flags.h"
 #include "src/frames.h"
@@ skipping 1131 matching lines @@
     }
   }
 
   // Abort execution if argument is a smi, enabled via --debug-code.
   void AssertNotSmi(Register object);
 
   // Abort execution if argument is not a smi, enabled via --debug-code.
   void AssertSmi(Register object);
   void AssertSmi(const Operand& object);
 
+  // Abort execution if argument is not a FixedArray, enabled via --debug-code.
+  void AssertFixedArray(Register object);
+
   // Abort execution if a 64 bit register containing a 32 bit payload does not
   // have zeros in the top 32 bits, enabled via --debug-code.
   void AssertZeroExtended(Register reg);
 
   // Abort execution if argument is not a JSFunction, enabled via --debug-code.
   void AssertFunction(Register object);
 
   // Abort execution if argument is not a JSBoundFunction,
   // enabled via --debug-code.
   void AssertBoundFunction(Register object);
@@ skipping 410 matching lines @@
 inline Operand StackOperandForReturnAddress(int32_t disp) {
   return Operand(rsp, disp);
 }
 
 #define ACCESS_MASM(masm) masm->
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_