a few things to fix & gdb

[Mark S. Miller <vlad!mark>]

Date: Sat, 22 Dec 90 07:24:57 PST
   From: xanadu!roger (Roger Gregory)

   There are a few places that our code is very fragile.  The one that
   causes the most debugging problems is that printOn often doesn't test
   to see that pointers are nonNULL.  ...  I have
   a routine that calls printOn when given an SPTR, but printOn tends to blow up.

Instead of having each printOn method check, how about having this
calling routine check?