Function safe_arch::bit_extract2_u64

#[must_use]pub fn bit_extract2_u64(a: u64, control: u64) -> u64

This is supported with target feature bmi1 only.

Extract a span of bits from the u64, control value style.

• Bits 0 through 7: start position.
• Bits 8 through 15: span length.

assert_eq!(bit_extract2_u64(0b0110, (3 << 8) | 0), 0b110);
assert_eq!(bit_extract2_u64(0b0110, (2 << 8) | 0), 0b10);
assert_eq!(bit_extract2_u64(0b0110, (2 << 8) | 1), 0b11);