* cygtls.cc (_cygtls::fixup_after_fork): Remove unneeded setting of oldmask.

* cygtls.cc (_cygtls::fixup_after_fork): Remove unneeded setting of oldmask.
* exceptions.cc: Remove some __I386__ conditionals.
(handle_exceptions): Move ppid test to outside of a loop for efficiency.
(setup_handler): Make debugging output more wordy.
(_cygtls::call_signal_handler): To avoid a race, use lock/unlock to synchronize
with signal thread and ensure that signal_arrived event has actually been set.
* gendef (_sigfe): Use ebx for all sigstack manipulations to ensure that the
register is saved.  Move setting of incyg to within stack lock to avoid
setup_handler confusion.
(_sigbe): Use ebx for all sigstack manipulations to ensure that the register is
saved.
(_cygtls::pop): Ditto.
(_cygtls::lock): Ditto.
(stabilize_sig_stack): Ditto.
(setjmp): Ditto.
(longjmp): Ditto.