linux threads support

[Hector Oron <hector.oron@gmail.com>]

Hello,

  Before Jessie was released, Robert Millan (rmh) managed to snick an
unupstreamed patch into GNU GDB
  http://sources.debian.net/src/gdb/7.7.1%2Bdfsg-5/debian/patches/linuxthreads_signal_handling.patch/

  The patch no longer applies as new signals have been added, I have
renumbered the signals and refresh that patch however it would be
useful to know if this is still relevant for Stretch release. My plan
is to drop it before freeze if none finds it useful in this list.

Regards,
-- 
 Héctor Orón  -.. . -... .. .- -.   -.. . ...- . .-.. --- .--. . .-.
  GDB maintainer hat