[Bug rtl-optimization/78116] [7 regression] Performance drop after r241173 on avx512 target

[ysrumyan at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78116

--- Comment #2 from Yuri Rumyantsev <ysrumyan at gmail dot com> ---
WE also found out performance drop on another important benchmark with the same
symptoms after r241170, namely loop marked with .L18 has +12 more fills from
stack. The test-case will be attached.