remove CFLAG setting of -fno-gcse, run autogen.sh

silence clang warning about unsupported flag. if we want
performance we have other ways to chase after it, the reason
for this specific flag has long since passed. if you're still
using gcc 3.4 there are plenty of other issues in modern slurm.

run autogen.sh to account for removal of auxdir/x_ac_cflags.m4