[Bug target/93594] Missed optimization with _mm256_set/setr_m128i intrinsics

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93594

--- Comment #4 from Marc Glisse <glisse at gcc dot gnu.org> ---
The versions involving _mm256_cast* may be related to PR50829 and others
(UNSPEC hiding the semantics of the operation).