Add Avx2 constant mask swizzle 8/16 and improve 32/64#1201

serge-sans-paille merged 1 commit intoxtensor-stack:masterxtensor-stack/xsimd:masterfrom

AntoinePrv:swizzle-avx2AntoinePrv/fork-xtensor-stack-xsimd:swizzle-avx2Copy head branch name to clipboard