] linux-user: sigaction fixes/cleanups
=== TEST SCRIPT BEGIN ===
#!/bin/bash
git rev-parse base > /dev/null || exit 0
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT
Alpha had two bugs, one with the non-ka_restorer fallback
using the wrong offset, and the other with the ka_restorer
value getting lost in do_sigaction.
Because do_sigaction didn't see TARGET_ARCH_HAS_SA_RESTORER
(which is correct for alpha, as the field isn't present in
the structure), we didn't
