[pve-devel] fix #2387: always save/restore FPU registers in ZFS SIMD helper

[Thomas Lamprecht]

see GitHub issue comments for some details:
https://github.com/zfsonlinux/zfs/issues/9346#issuecomment-534984486
https://github.com/zfsonlinux/zfs/issues/9346#issuecomment-535133283

and the two patches for remaining ones.

If this looks OK I can apply and push this out, the patch which updates
the zol submodule in pve-kernel obviously misses but I have all ready local if
nobody sees anything wrong in the patches.