Revert r360606, as it results in linker set errors while building for
amd64, I'll have to re-do this more carefully:

Un-MFC r354043 (partial, by sjg):

Add support for hypervisor check on x86

Add ficl words for isvirtualized
and move ficl inb and outb words to ficl/x86/sysdep.c
so can be shared by i386 and amd64

Reviewed by: imp bdrewery
Sponsored by: Juniper Networks
Differential Revision: https://reviews.freebsd.org/D22069