…tion
Currently DECLARE_SIMD emits a "not yet implemented" error in the MLIR
to LLVM IR translation.
DECLARE_SIMD is a hint to the compiler and ignoring it is technically
speaking a conforming implementation (although obviously not desirable).
Do not abort compilation when DECLARE_SIMD is encountered, but emit a
warning that it's currently ignored.
(cherry picked from commit 5ca62fdee645ec253263e41a45fe626c6b66be22)
Fixes: https://github.com/llvm/llvm-project/issues/234108