Function poly_blep_simd

pub fn poly_blep_simd<S: Sample>(t: S::Simd, dt: S::Simd) -> S::Simd

Branchless SIMD PolyBLEP correction for 4 phase values.

Computes all branches and selects using masks for efficient vectorization. The branches are mutually exclusive when dt < 0.5 (valid for all practical oscillator frequencies below Nyquist/2).