Function cm_block_buffer_copy_data_bytes 

pub unsafe extern "C" fn cm_block_buffer_copy_data_bytes(
    block_buffer: *mut c_void,
    offset_to_data: usize,
    data_length: usize,
    destination: *mut c_void,
) -> i32

Swift bridge function cm_block_buffer_copy_data_bytes for the corresponding Apple API.