ARC/signal: shield sa_restorer from compiler toggle side-effects
when building uClibc with -O0 (DODEBUG build) the default sigrestorer
had some extra glue code generated for stack manipulation which was
messing up resume from signal path.
So annotate the function with -Os so that gcc would only generate the
bare min 2 instruction TRAP sequence
Reported-and-Debugged-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>