[MIPS] Extend Signal Mapping to include RT Signals.

Both MIPS and ARM use signals 32 to 64 for real-time signals.
ARM signals 32 to 64 can't be masked due to the signal
mask being limited to 32 bits. MIPS signals 32 to 64 can be
masked, and Lib-Portable correctly supports this feature.

Fixes LTP tests rt_sigaction01 and ptrace05.

Fixed a few signal problems; Ex last Real Time Signal

1.  The signal handler for signal number 64, the last real
    time signal, wasn't being intercepted. Now catching
    signal number 64.

2.  sigaction() to only change *oldact when return
    value is zero.

3.  Fixed rt_sigqueue_portable() to set errno when
    returning a -1.

4.  Fixed a few cases where signal 0 was being added
    to the table of signal handlers for signal remapping.
    Harmless but a bit silly.

Change-Id: I1a71113d7ce4b60f3a587dae4e243dc88dd6d6bc
Signed-off-by: Pete Delaney <piet.delaney@imgtec.com>
Signed-off-by: Chris Dearman <chris.dearman@imgtec.com>
Signed-off-by: Paul Lind <paul.lind@imgtec.com>
2 files changed