Fix Issue 20160 - ThreadInfo.cleanup() clears local thread's...

[ghost]

This is a copy of PR #7152. For what ever reason the original author insisted on not adding a unittest (which exists in bugzilla) and finally closed that issue.

[dlang-bot]

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	20160	normal	ThreadInfo.cleanup() clears local thread's registered names instead of "this"'s

Testing this PR locally

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

dub fetch digger
dub run digger -- build "master + phobos#7314"

[ghost]

Errorlog from buildkite/phobos:

dmd: /var/lib/buildkite-agent/builds/ci-agent-75519bae-71c7-4594-b0ef-8e01a27fe867-3/dlang/phobos/dmd/src/dmd/backend/cgcod.d:2491: Assertion `cast(int)(*e).Ecomsub <= cast(int)(*e).Ecount' failed.

I don't know if this is triggered by this PR or something else...

[thewilsonator]

That shows up on other PRs, so no.