* get_signal_stack() checked the wrong sig_action field (index is signal-1), also,
it had an off-by-one error in the stack range check.
* factored out a restart_syscall() function to avoid code duplication
* arch_setup_signal_frame() relied on the fact that vregs and the signal stack code
is a multiple of 4 bytes in size.
* Fixed sigaction(): it did return the error code directly instead of setting errno.
* signal() actually had a work-around for the broken sigaction()...
* Replaced the sig_func_t typedef with a sighandler_t typedef - this is non-standard
anyway, but now we're at least compatible with the GNU world instead of introducing
our own solution (BSD seems to use sig_t here, BTW).
* Removed now unused sigval structure from the header; it should be added again as
soon as we start supporting it.
* SA_RESETHAND and SA_ONESHOT are the same thing; the former did not work before.
* Made the non-standard SA_* flags refer to the standard ones instead of the other
way around.
* Added a test application for various signal features - works fine under Haiku,
tested also under Linux and BeOS (the latter fails as it does not support SA_RESTART).
More tests should be added, though.
* Cleanup.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21999 a95241bf-73f2-0310-859d-f6bbb57e9c96
a728651f04