[Gc] In bdwgc, do finalizers need to be strictly async-signal safe?

[Jean-Claude Beaudoin]

Objviously my question takes its full meaning in a POSIX context
(like Linux) but I think it still is somewhat relevant to other
non-POSIX situations (like MS-Windows).

Sorry if the question is too naive or is a FAQ of some sort
but I could not find a clear and direct answer in the documentation
at hand.

Thanks,

Jean-Claude Beaudoin