Merged in new upstream version of the maxopt autotools macros that fixes the problem or erasing the CFLAGS.
See http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=commitdiff;h=73ee1b396c21062ee8eeb8721ba5323322110fb5 for the upstream commit.
This allows us to remove the workaround that was built into our configure script.