patch to ignore SIGPWR and SIGXCPU (used by pthreads)

[Michael Snyder]

Andrew Cagney wrote:
> 
> > Why not?  What does it hurt to (by default) just pass them to the
> > inferior?  Having gdb stop inconveniences (and confuses) everybody who
> > uses gcj.  Having gdb silently pass the signals to the application
> > inconveniences/confuses - who?
> 
> Consider SIGXCPU.
> 
> With your proposed change, a program that exceeds its CPU usage will
> quietly terminate.   The user will loose their entire debug session.
> This is very different to GDB's current behavour where the signal is
> intercepted, the program is stopped, and control is returned to the user.


Java's use of these signals is somewhat analogous to what
linux threads does.  In that case, we also "silence" the 
signals, but we do it only in the context where we know
they are used.  Only for linux, and only when a multi-thread
program is detected.

Could you do something like that?