Haswell zgemmt failures

[chillenb]

Starting at commit 5d9332e,

./configure -t openmp haswell
make
BLIS_NUM_THREADS=4 make check

fails the following tests:

blis_zgemmt1m_unn_ccc                    100   100    31.67       -nan   FAILURE
blis_zgemmt_unn_ccc                      100   100    35.18       -nan   FAILURE

GCC 16.2.1

I started getting nans from TBLIS after bumping the BLIS version, but only with the haswell ukr. These went away after reverting to the previous tag (5c2b22d).