MFC 267963:
The latest versoin of file/libmagic identifes a filesystem image
is identified as "DOS/MBR boot sector" as opposed to "x86 boot sector".

This trips up vmrun.sh when using the new file(1) and makes it want to boot
into the installer instead.

Fix this by just looking for "boot sector" instead.
MFC	r268290:
Merge from OpenSolaris (24-Jul-2010):

6679140 asymmetric alloc/dealloc activity can induce dynamic variable drops
6679193 dtrace_dynvar walker produces flood of dtrace_dynhash_sink

This finishes a set of merges from the older OpenSolaris releases.
Still the FreeBSD port has many differences that are difficult to
account for but that seems normal given that the kernels are different.

Obtained from:	OpenSolaris (through Illumos)