[Bug target/92437] Unnecessary register duplication of vector constant in x86

[zingaburga+gcc at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92437

--- Comment #2 from zingaburga+gcc at hotmail dot com ---
Thanks for the info Andrew!
Changing the add to `_mm_add_epi64` does seem to eliminate all instances of the
duplication.