suzerain: bump tols for GCC 4.8

-O3 on GCC 4.8 shows larger mismatches than GCC 4.6 did,
but nothing terribly alarming in the absolute sense.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@44140 0bd85f0b-c151-43b9-a1e9-27231104551f