
Enable PAE mode for those CPUs that support it. This allows us to use the
NX bit for userland and kernel W^X. Unlike the previous c.2008 PAE
experiment, this does not provide > 4GB phys ram on i386 - PAE is solely
being used for NX capability this time. If you need > 4GB phys, use amd64.

Userland W^X was committed yesterday by kettenis@, and we will shortly
start reworking the kernel like we did for amd64 a few months back to get
kernel W^X.

This has been in snaps for a few days and tested by kettenis and myself
as well.

ok deraadt@, kettenis@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars