change unconditional x86-64-v4 reliance to the former x86-64-v2 reliance#15

ultrabear wants to merge 1 commit intoawesomized:mainawesomized/crc-fast-rust:mainfrom

ultrabear:fix/incorrect_target_featuresultrabear/forked_crc-fast-rust:fix/incorrect_target_featuresCopy head branch name to clipboard