Merge tag 'arc-4.0-fixes-part-2' of git://

Pull ARC fixes from Vineet Gupta:
 "We found some issues with signal handling taking down the system.  I
  know its late, but these are important and all marked for stable.

  ARC signal handling related fixes uncovered during recent testing of
  NPTL tools"

* tag 'arc-4.0-fixes-part-2' of git://
  ARC: signal handling robustify
  ARC: SA_SIGINFO ucontext regs off-by-one