[Bug target/92686] Inefficient mask operation for 128/256-bit vector VCOND_EXPR under avx512f

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92686

--- Comment #3 from Hongtao.liu <crazylht at gmail dot com> ---
Created attachment 47372
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47372&action=edit
Local patch with Bootstrap and regression test on i386/x86_64 is ok.

Also I found there are some disturb with pr88547.