core files in testsuite directory

[David Carlton <carlton@kealia.com>]

My testsuite directory is littered with core files.  They're from
annota1, annota3 (the one in gdb.base, not the one in gdb.cp), and
signals.  The first two tests attempt to remove a file named 'core',
but the core files are actually named 'core.PID', so they stay around.

Some questions:

* I assume that all these tests are generating core files for
  legitimate reasons?  It's not entirely clear to me why they're being
  generated, but I don't really understand what signals lead to core
  files in the first place.

Assuming that's the case, we should presumably change the core file
cleanup function (and move it to lib/gdb.exp, for ease of sharing, and
have signals.exp call it as well).  So:

* What should the new cleanup function do?  Should it just try to
  remove core.*?  Or should it be passed the PID of the process in
  question, and only try to remove core.PID and core?

David Carlton
carlton@kealia.com