[Ecls-list] Attach-GDB restart in Slime CVS

[Tobias C. Rittweiler]

I just added an ATTACH-GDB restart to Slime CVS which attachs runs 
gdb -p <ecl's pid> in an Emacs buffer.

It's often not obvious where exactly an error comes internally from
because the Lisp backtrace only contains Lisp functions, and perhaps not
even all internal Lisp functions (not sure about the last point,
unchecked hypothesis based on superficial impression.)

So you can know conveniently switch over to gdb, and get a C backtrace
there. Make sure to build ECL with --with-debug-cflags.

  -T.