Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version

- Fixed warnings
- Fixed deadlock in xsi_sem_undo - RecordUndo
- Fixed issue in xsi_sem_undo: if the semaphore set does not exist
anymore, ignore the request but do remove the process from the sUndoList,
which wasn't previously done.
- free() in ClearUndos was called with interrupts disabled
- when a semaphore set ends to exist, remove all it's sem_undo request as it's ID
will be reused in the future.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26727 a95241bf-73f2-0310-859d-f6bbb57e9c96

First patch by Salvatore to implement XSI semaphores with a few changes
by myself:
* renamed xsi_do_undo() to xsi_sem_undo() (there is more to XSI than sems).
* Fixed coding style issues in sys/sem.h and xsi_sem.cpp.
* Added _kern_*() syscall prototypes to syscalls.h.
* Added a TODO in xsi_sem.cpp and xsi_semaphore.h about moving union semun to
a shared header.
* Made the team::xsi_sem_undo_requests int32 - due to padding, it would have
needed 4 bytes anyway; please always use specific types over int/short/long.
* xsi_sem_undo() now checks if it needs to do anything - the calls in team.cpp
no longer needs to do this.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26676 a95241bf-73f2-0310-859d-f6bbb57e9c96

Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version

- Fixed warnings
- Fixed deadlock in xsi_sem_undo - RecordUndo
- Fixed issue in xsi_sem_undo: if the semaphore set does not exist
anymore, ignore the request but do remove the process from the sUndoList,
which wasn't previously done.
- free() in ClearUndos was called with interrupts disabled
- when a semaphore set ends to exist, remove all it's sem_undo request as it's ID
will be reused in the future.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26727 a95241bf-73f2-0310-859d-f6bbb57e9c96

First patch by Salvatore to implement XSI semaphores with a few changes
by myself:
* renamed xsi_do_undo() to xsi_sem_undo() (there is more to XSI than sems).
* Fixed coding style issues in sys/sem.h and xsi_sem.cpp.
* Added _kern_*() syscall prototypes to syscalls.h.
* Added a TODO in xsi_sem.cpp and xsi_semaphore.h about moving union semun to
a shared header.
* Made the team::xsi_sem_undo_requests int32 - due to padding, it would have
needed 4 bytes anyway; please always use specific types over int/short/long.
* xsi_sem_undo() now checks if it needs to do anything - the calls in team.cpp
no longer needs to do this.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26676 a95241bf-73f2-0310-859d-f6bbb57e9c96