Make the skylakex/haswell sgemm code compile and run even with compilers without avx2 support
Make the skylakex/haswell sgemm code compile and run even with compilers without avx2 support

xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS