[CI] Restrict to newer clang.
Clang before 3.9 does not have the intrinsic _mm_rolv_epi32()
, which is used
by vectorclass if the avx512vl instruction set is available.
Edited by Jö Fahlke
Clang before 3.9 does not have the intrinsic _mm_rolv_epi32()
, which is used
by vectorclass if the avx512vl instruction set is available.