The test expects the number of registered script sources to stay the same across a profiler disable/enable cycle. On sm-compacting builds a zeal GC can run between the two enableGeckoProfiling calls and discard the JitScripts of scripts that are no longer on the stack (prologue.js and self-hosted), so their sources don't get re-registered on the second enable and the counts no longer match. Disable GC zeal at the start of the test to keep it deterministic. Differential Revision: https://phabricator.services.mozilla.com/D312038