[Bug target/70927] avx512dq instructions emitted even with -mavx512vl -mno-avx512dq

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70927

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 38406
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38406&action=edit
gcc7-pr70927.patch

Untested fix.