[Bug target/121099] GCC doesn't optimize `_mm_set_ps()` very well

[lh_mouse at 126 dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121099

--- Comment #1 from LIU Hao <lh_mouse at 126 dot com> ---
Given `y` in XMM0 and `x` in XMM1, `_mm_set_ps(x, x, y, y)` is clearly just
`vshufps xmm2, xmm0, xmm1, 0` no matter what.