asyncsafe-spin: Fix race condition on native Windows. * lib/asyncsafe-spin.h (asyncsafe_spin_lock, asyncsafe_spin_unlock): Add from_signal_handler parameter. * lib/asyncsafe-spin.c (asyncsafe_spin_lock, asyncsafe_spin_unlock): Likewise. * modules/asyncsafe-spin (Depends-on): Add bool. * tests/test-asyncsafe-spin1.c (main): Update. * tests/test-asyncsafe-spin2.c (lock_mutator_thread, lock_checker_thread): Update. * lib/clean-temp-simple.c (clean_temp_asyncsafe_close): Update. * lib/clean-temp.c (asyncsafe_fclose_variant): Update.