anchor.diff:  
   (defmethod cleavir-ir:specialize
       ((instruction cleavir-ir:rplaca-instruction)
  -     (implementation sicl-target-sicl:sicl
  +     (implementation sicl-target-sicl:sicl)
        (processor cleavir-processor-x86-64:x86-64)
        os)
     (declare (ignore os))
  
positive.code: 
  (defmethod cleavir-ir:specialize
      ((instruction cleavir-ir:car-instruction)
       (implementation sicl-target-sicl:sicl
       (processor cleavir-processor-x86-64:x86-64)
       os)
    (declare (ignore os))
  
negative.code: 
  (defmethod cleavir-ir:specialize
      ((instruction cleavir-ir:cdr-instruction)
       (implementation sicl-target-sicl:sicl)
       (processor cleavir-processor-x86-64:x86-64)
       os)
    (declare (ignore os))
  