Steps to reproduce:

1. Download and open PixarKitchen project (pull denoiser-trouble branch)
2. Make sure that lightmapper is set to Progressive GPU
3. Enable advanced filtering
4. Select OpenImageDenoise as denoiser
5. Bake the lighting
6. Notice that the output is still noisy in places

Notes:

- Regression introduced in: 2020.1.0a24
- Reproduces in: 2020.1.4f1, and 2020.2.0a19
- Does not reproduce in: 2020.1.0a11
- Has regressed some time after 2020.1.0a17
- Mostly affects the GPU lightmapper, although CPU lightmapper output also exhibits some noise