Function apply_polyblep_pulse

pub fn apply_polyblep_pulse<S>(
    samples: &mut [S; 4],
    phases: [S; 4],
    phase_inc: S,
    duty_cycle: S,
)
where
    S: Sample,

Apply PolyBLEP corrections to a SIMD chunk of pulse samples.

Uses branchless SIMD for both rising (phase=0) and falling (phase=duty_cycle) edges.