f76e5fba

By: Tom Sydney Kerckhove <syd@cs-syd.eu>

Run the asynchronous-runner regression tests sequentially

Each test tears a nested runner down mid-flight, cancelling its worker,
printer and scheduler threads.  Running that alongside the rest of the
suite made the suite abort with 'free(): invalid pointer' under load:
with the fix but without these tests the suite survived 3 load rounds,
and with them it died in 1 of 2.
GitHub
Time to Start Worker time Duration Time to finish Idle
Config 6m03s 1s 1s 6m04s 6m03s
Eval - - - - 3m54s
Build - - - - -
Suite 6m03s 1s - - 9m57s