std.logger 32 bit unittest race condition fix

[burner]

@WalterBright maybe this helps. From the errors I saw, there is a race somewhere on 32 bit.

[dlang-bot]

Thanks for your pull request, @burner!

Bugzilla references

Your PR doesn't reference any Bugzilla issue.

If your PR contains non-trivial changes, please reference a Bugzilla issue or create a manual changelog.

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + phobos#8553"

[burner]

thank you

[pbackus]

Same test is still failing for me in #8555

[pbackus]

Judging from the message I saw (foo), the race is between the test modified in this PR and this test, which also accesses sharedLog.

[burner]

I think I understand the problem. The created thread executes code after the test is done. It has to be joined before the test is over. I'll create a PR.