Make some constants' meaning clear for X64

src/x64/macro-assembler-x64.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 819 matching lines @@
   void Jump(Handle<Code> code_object, RelocInfo::Mode rmode);
 
   void Call(Address destination, RelocInfo::Mode rmode);
   void Call(ExternalReference ext);
   void Call(Handle<Code> code_object,
             RelocInfo::Mode rmode,
             TypeFeedbackId ast_id = TypeFeedbackId::None());
 
   // The size of the code generated for different call instructions.
   int CallSize(Address destination, RelocInfo::Mode rmode) {
-    return kCallInstructionLength;
+    return kCallSequenceLength;
   }
   int CallSize(ExternalReference ext);
   int CallSize(Handle<Code> code_object) {
     // Code calls use 32-bit relative addressing.
     return kShortCallInstructionLength;
   }
   int CallSize(Register target) {
     // Opcode: REX_opt FF /2 m64
     return (target.high_bit() != 0) ? 3 : 2;
   }
@@ skipping 688 matching lines @@
     masm->popfq();                                                           \
   }                                                                          \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_