Anton Shestakov <av6@dwimlabs.net> [Mon, 02 Dec 2019 20:56:47 +0700] rev 4979
test-compat: run tests with -j more than 1
In 4.7 and below run-tests.py defaults to -j1. We want more speed, so we use
the same mechanism to detect the available number of CPU threads as the newer
versions of run-tests.py.