On Blackfin systems, the hardware single step exception triggers before the system call exception, so we need to save this info to process it later on. Otherwise, single stepping in userspace misses a few insns right after the system call. This is based a bit on the SuperH code added in commit 4b505db9c4c72dbd. Reported-by: Roland McGrath <roland@redhat.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>