_cygtls::interrupt_now.
(_cygtls::handle_exceptions): Handle STATUS_DATATYPE_MISALIGNMENT as
SIGBUS error. Differ between unmapped memory (SEGV_MAPERR) and access
violation (SEGV_ACCERR) in case of STATUS_ACCESS_VIOLATION. Write
kernel log message in case of uncatched STATUS_ACCESS_VIOLATION.
(_cygtls::interrupt_now): Just call interruptible now instead of
evaluating interruptibility here.