Hello

While studying how signals are handled in Emacs (both when run under a
POSIX system as well as MS-Windows) and also how GDB deals with them, I
thought it would be worth to revise the section 'Getting control to the
debugger' in etc/DEBUG to include some more information about how
signals can be used to interrupt Emacs debuggee and return control back
to GDB.

Would you mind installing this patch?  Any comments are welcome.

Thanks
Alain