When do thread-local dtors execute relative to thread blocked on "join"?

[RalfJung]

I just realized that currently, Miri unblocks threads joining on some other thread before running the TLS dtors of that thread. That seems odd to me, is that really the right semantics?

Cc @vakaras

[RalfJung]

This example shows that probably we should run dtors before waking up threads that join.

[vakaras]

Good point. I somehow have not thought about this.