Function i16x8_extmul_low_u8x16

#[target_feature(enable = "simd128")]
pub fn i16x8_extmul_low_u8x16(a: v128, b: v128) -> v128

Lane-wise integer extended multiplication producing twice wider result than the inputs.

Equivalent of i16x8_mul(i16x8_extend_low_u8x16(a), i16x8_extend_low_u8x16(b))