Function handle_mutable_buffer_remainder_unary 

fn handle_mutable_buffer_remainder_unary<F>(
    op: &mut F,
    start_remainder_mut: &mut [u8],
    remainder_len: usize,
)
where
    F: FnMut(u64) -> u64,

Handle remainder bits (< 64 bits) for unary operations.

This function processes the bits that don’t form a complete u64 chunk, ensuring that bits outside the operation range are preserved.

Arguments

• op - Unary operation to apply
• start_remainder_mut - Slice of bytes to write the remainder bits to
• remainder_len - Number of remainder bits