anchor.diff:                           (emit-gc-info)))
                      (emit-lap backend-function inst-or-label uses defs))))
             (values (reverse *emitted-lap*)
  -                  debug-layout))))))
  +                  debug-layout
  +                  environment-slot))))))
   
   (defmethod lap-prepass (backend-function (instruction argument-setup-instruction) uses defs)
     (when (argument-setup-rest instruction)
  
positive.code: (defun to-lap (backend-function)
    (multiple-value-bind (uses defs)
        (mezzano.compiler.backend::build-use/def-maps backend-function)
      (multiple-value-bind (*stack-layout* debug-layout)
          (compute-stack-layout backend-function uses defs)
        (let ((*saved-multiple-values* (make-hash-table))
              (*dx-root-visibility* (make-hash-table))
  
negative.code:     (sys.int::assemble-lap
       lap
       (backend-function-name backend-function)
       (let* ((ast-lambda (mezzano.compiler.backend::ast backend-function)))
         (list :debug-info
               (backend-function-name backend-function) ; name
               debug-layout ; local variable stack positions
               ;; Environment index
               environment-slot
               ;; Environment layout
               (second (sys.c:lambda-information-environment-layout ast-lambda))
               ;; Source file
               (if *compile-file-pathname*
                   (namestring *compile-file-pathname*)
                   nil)
               ;; Top-level form number
               sys.int::*top-level-form-number*
               (sys.c:lambda-information-lambda-list ast-lambda) ; lambda-list
               (sys.c:lambda-information-docstring ast-lambda))) ; docstring
       nil
       :x86-64)))
  
  