[commit] Overhaul signals.exp

[Andrew Cagney]

> Approved.
> 
> Michael C
> 
> ===
> 
> 2004-07-12  Andrew Cagney  <cagney@gnu.org>
> 
> 	* gdb.base/signals.exp: Replace send_gdb and gdb_expect with
> 	gdb_test and gdb_test_multiple.  Delete bash_bug.  Delete suspect
> 	XFAILs.  Clean up test messages and comments.  Check backtraces.
> 	Delete re-sync code.

Oops, I forgot to commit this, doing it now.

Andrew