[CFT] gcc can cause segfaults in ctfmerge

[Pedro Giffuni]

Hi;

I have been following a fix to ctfmerge that was done on NetBSD and
is caused by a bug in upstream gcc. The issue is summarized here:

https://www.illumos.org/issues/3776

I have a patch for FreeBSD here:

http://people.freebsd.org/~pfg/patches/patch-dtrace-gcc.diff

The process to get some change into illumos seems to be somewhat
complex but the issue is not urgent for us as our base gcc was fixed.

The patch will be important once we drop gcc from the base system
and start using more frequently the pre-packaged gcc though so some
more testing/review on this patch is welcome.

regards,

Pedro.