Code to produce bug:
(setq lf 134477)
(with-open-file (out "result.lisp"
:direction :output :if-exists :supersede)
(format out "(EXT:! ~A)~%" lf)))
(EXT:SHELL "time clisp -c result.lisp")
(EXT:SHELL "time clisp result.fas")
NOTE!! (EXT:! 134477) in interactive mode, and *IN THE COMPILE* pass the test!!!!
The factorial of 134477 fits into BIGNUM just fine.
This also means (load) will fail on legal BIGNUMs