sys/user.h is a stub that just #includes sys/pcb.h.
There are no 'struct pcb' anywhere in here, so I'm extremely doubtful
any of the builds will fail.
OTOH it might be relying on a header that pcb.h includes.
In any case i386 and amd64 build.
- add kvm_i386pae.c (used for PAE memory translations), and update Makefile
for libkvm build.
- in pdppaddr: pass a flag to indicate PAE mode. Use a bit ignored
by the MMU. Mask address with PG_FRAME to avoid side effects.
Tested with vmstat(1)/netstat(1) to debug core files of PAE and !PAE
kernels. Older kernel dumps will default to native i386 (!PAE) mode.
XXX Currently, savecore(8) will fail to dump a PAE kernel in a !PAE
environment (and reciprocally). So you need to sync and reboot
with a kernel of the same mode as the one that crashed. Once the dump
is successful, this does not matter anymore.
