Hello,

This patch follows up a proposed change from long ago.  Update things so 
that when in batch mode (i.e. no tty) an internal-error will:

	quit
	dump core

this adjusts things accordingly.  For the user, the resultant behavour is:

(gdb) maint internal-error
gdb/maint.c:119: gdb-internal-error: internal maintenance
An internal GDB error was detected.  This may make further
debugging unreliable.  Quit this debugging session? (y or n) y

Create a core file containing the current state of GDB? (y or n) y
Abort trap (core dumped)
ac131313@nettle$

Unless someone raises a problem.  I'll commit it in a few days.

enjoy,
Andrew