CI jobs that run threaded programs under LSan has been giving false
positives from time to time, which has been worked around.
This is an alternative to the jk/lsan-race-with-barrier topic with
much smaller change to the production code.
* jk/lsan-race-ignore-false-positive:
test-lib: ignore leaks in the sanitizer's thread code
test-lib: check leak logs for presence of DEDUP_TOKEN
test-lib: simplify leak-log checking
test-lib: rely on logs to detect leaks
Revert barrier-based LSan threading race workaround
effbef2beb