LISPT, CHNTB, LDDT, SYMBOLS, AND SCREWAGE

[HMR at MIT-MC (Harry M. Rath)]

Ah, I've found what was causeing all my lossage, I think.
Loading LDDT without symbols is a screw.  J*STADR and friends
do not get defined, being GETDDTSYM'd values which are passed to
(STORE (ARRAYCALL FIXNUM JOB J*STADR) ..) and such.  This is certainly
what was causing the job interrupt handler to be clobbered with 4000
(and later .ATOM CRLF), and quite likely it was also causing the array
to get clobbered just enough to cause the channel to not get deallocated
by the GC.  Probably this has been the source of all my bugs.

I added the syms J.STADR and J.CRUFT to XTRSYMS, but in the meantime maybe
LDDT should explicitly load symbols if needed?