Extends the invariant-8 primitives list with the new gradient-noise
family: the constant-retargeting for snoise_grad, the per-octave
frequency/amplitude chain rule, ridged_grad's deliberate zero crease,
and the octave clamp's reason (the HLSL mirror test's bit-parity
oracle).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
03f0ed7a0a