MFC r251591:
The vm_page lock is not needed around the call to vm_page_insert().
MFC r251283:
MFamd64: when printing the trap information, show the %esp value.
MFC r251324:
Assert that interrupts are enabled in the trap handlers on x86 before
calling generic code to deliver signals.
MFC r251424:

New install flags were merged to 9-STABLE and will appear in
FreeBSD-9.2.

Sponsored by:	DARPA, AFRL
Submitted by:	ru
Merge remote-tracking branch 'upstream/stable/9' into stable/9