Rollup merge of #120430 - devnexen:fix_tls_dtor_fbsd, r=cuviper

std: thread_local::register_dtor fix proposal for FreeBSD.

following-up 5d3d347 commit, rust started to spin
__cxa_thread_call_dtors warnings even without any TLS usage. using instead home made TLS destructor handler `register_dtor_fallback`.

close #120413

Author: Nadrieril