Document GPU kernel audit progress

PerfectNumbers.Core/Gpu/Kernels/NttPointwiseKernels.cs

@@ -0,0 +1,20 @@
+using ILGPU;
+
+namespace PerfectNumbers.Core.Gpu;
+
+internal static class NttPointwiseKernels
+{
+    public static void MulKernel(Index1D index, ArrayView<GpuUInt128> a, ArrayView<GpuUInt128> b, GpuUInt128 modulus)
+    {
+        var val = a[index];
+        val.MulMod(b[index], modulus);
+        a[index] = val;
+    }
+
+    public static void ScaleKernel(Index1D index, ArrayView<GpuUInt128> data, GpuUInt128 scale, GpuUInt128 modulus)
+    {
+        var v = data[index];
+        v.MulMod(scale, modulus);
+        data[index] = v;
+    }
+}