Function _mm_mulhrs_epi16
#[target_feature(enable = "ssse3")]
pub fn _mm_mulhrs_epi16(a: __m128i, b: __m128i) -> __m128iMultiplies packed 16-bit signed integer values, truncate the 32-bit
product to the 18 most significant bits by right-shifting, round the
truncated value by adding 1, and write bits [16:1] to the destination.