Workaround for Lucid Lisp 2.0.4 bug

[Timothy.Freeman@theory.cs.cmu.edu]

The bug is that the Lucid compiler passes something useless as the
&environment parameter to macros that are expanded at compile time.
This little file illustrates the bug because a segmentation violation
happens when we try to compile it:

   (defun make-lexical-environment (environment)
     (evalhook '(labels ((bar ())) (make-lexical-environment-2))
	       'make-lexical-environment-1
	       ()
	       environment))
   
   (defun make-lexical-environment-1 (form env)
     (setq form (macroexpand form env))
     (evalhook form  'make-lexical-environment-1 nil env))
   
   (defmacro make-lexical-environment-2 (&environment env)
     (list 'quote (copy-tree env)))
   
   (defun foo ()
     (macrolet ((baz (&environment env)
		     (format t "Env is ~S.~%" env)
		     (inspect env)
		     (make-lexical-environment env)
		     3))
	       (baz)))

The bug causes PCL (dated 4/29/87 prime) to get a segmentation
violation when it tries to walk forms with labels constructs.  The
workaround I found is to change the definition of expand-defmethod in
boot.lisp as follows.  The surplus call to walk-form prevents the
macros from being called directly by the compiler.

***************
*** 142,148
  
  
  (defun expand-defmethod (name qualifiers arglist body)
!   (let ((defmethod-uid (gensym))
  	(load-method-1 ()))
      (multiple-value-bind (parameters lambda-list specializers)
  	(parse-specialized-lambda-list arglist)

--- 142,149 -----
  
  
  (defun expand-defmethod (name qualifiers arglist body)
!    (walker:walk-form
!     (let ((defmethod-uid (gensym))
  	(load-method-1 ()))
      (multiple-value-bind (parameters lambda-list specializers)
  	(parse-specialized-lambda-list arglist)
***************
*** 199,205
  				       name
  				       defmethod-uid
  				       load-method-1
! 				       real-body)))))))))
  
  (defun make-top-level-form (form)
    #-Symbolics form

--- 200,206 -----
  				       name
  				       defmethod-uid
  				       load-method-1
! 				       real-body))))))))))
  
  (defun make-top-level-form (form)
    #-Symbolics form