comp.lang.lisp needs to stop complaining about overcommit

or: How I got sucked back into SBCL hacking on Christmas.

: david@radon:~; ps -o pid,vsz,rss,comm -p `pidof sbcl`
  PID    VSZ   RSS COMMAND
 1019 570424  4424 sbcl
: david@radon:~; ps -o pid,vsz,rss,comm -p `pidof sbcl`
  PID    VSZ   RSS COMMAND
 1019 963320 404204 sbcl
: david@radon:~; ps -o pid,vsz,rss,comm -p `pidof sbcl`
  PID    VSZ   RSS COMMAND
 1019 3988328 825804 sbcl