* [3.6] bpo-30703: Improve signal delivery (GH-2415)
* Improve signal delivery
Avoid using Py_AddPendingCall from signal handler, to avoid calling signal-unsafe functions.
* Remove unused function
* Improve comments
* Add stress test
* Adapt for --without-threads
* Add second stress test
* Add NEWS blurb
* Address comments @haypo.
(cherry picked from commit c08177a1cc)
* bpo-30796: Fix failures in signal delivery stress test (#2488)
* bpo-30796: Fix failures in signal delivery stress test
setitimer() can have a poor minimum resolution on some machines,
this would make the test reach its deadline (and a stray signal
could then kill a subsequent test).
* Make sure to clear the itimer after the test
Antoine Pitrou