[RFT] llquantize for FreeBSD's dtrace

Hello;

I am not a Dtrace user (yet) but I started to port the Log/linear
quantizations from Illumos:

http://dtrace.org/blogs/bmc/2011/02/08/llquantize/

Apparently this patch should do it:

http://people.freebsd.org/~pfg/patches/patch-llquantize-complete

Unfortunately when I tried to build current with Dtrace support,
my i386 Virtualbox VM got stuck in ctfmerge so this is
completely untested.

Testers that know how to use it are welcome :).

best regards,

Pedro.

ps. just for reference, the original code was taken from here:
https://hg.openindiana.org/upstream/illumos/illumos-gate/rev/15b74a2a9a9d