[test/barrier] Make the barrier test run the barrier 50 times in a row.
[test/barrier] Make the barrier test run the barrier 50 times in a row.

mit-carbon/Graphite,victorisildur/Graphite,mit-carbon/Graphite-Cycle-Level,mit-carbon/Graphite-Cycle-Level,8l/Graphite,mit-carbon/Graphite,nkawahara/Graphite,nkawahara/Graphite,victorisildur/Graphite,nkawahara/Graphite,8l/Graphite,fhijaz/Graphite,mit-carbon/Graphite-Cycle-Level,8l/Graphite,8l/Graphite,victorisildur/Graphite,fhijaz/Graphite,nkawahara/Graphite,mit-carbon/Graphite,fhijaz/Graphite,mit-carbon/Graphite-Cycle-Level,victorisildur/Graphite,fhijaz/Graphite,mit-carbon/Graphite