yacc_tests needs to be run by an unprivileged user

If it's run as root almost all of the "nosuchfile" testcases will fail

Sponsored-by: EMC / Isilon Storage Division
Remove all modifications to run_test.sh

The issue has been root-caused to the fact that FreeBSD permits file
access as root, regardless of mode. This is a known caveat on FreeBSD:
http://lists.gnu.org/archive/html/bug-bash/2010-07/msg00071.html

Sponsored-by: EMC / Isilon Storage Division