//! Base Priority Mask Register (conditional write)
/// Writes to BASEPRI *if*
///
/// - `basepri != 0` AND `basepri::read() == 0`, OR
/// - `basepri != 0` AND `basepri < basepri::read()`
///
/// **IMPORTANT** If you are using a Cortex-M7 device with revision r0p1 you MUST enable the
/// `cm7-r0p1` Cargo feature or this function WILL misbehave.