Anamorphic Squeeze Factor causes a blocky Depth of Field issue on AMD Hardware

When using the Anamorphic Squeeze Factor on a camera on AMD RDNA3 and RDNA4 hardware, blocking artefacts may be seen depending on the extent of the blur. The peripheries of the viewport appear to be affected first.

This issue appears on RDNA3 hardware and has been reported on RDNA4 hardware.
Reproduction on AMD RDNA2 is unconfirmed and the issue is not exhibited on base console platforms.
Additionally, NVIDIA Ampere hardware does not exhibit this issue, and the DoF resolves correctly as expected.

Additionally, setting CONFIG_WAVE_BROADCAST_REDUCTION to zero will cause RDNA3 and RDNA4 to render the image as expected.

1. (Optional) Modify the engine to allow Anamorphic Squeeze Factor to be set above 2. This makes the repro visible more readily.
2. Place a line of objects. It helps with noticing the issue if these have greebles or other surface interest.
3. Line a camera up with these and slowly move the camera. Keep the nearest object in the near DoF blur. Moving the camera such that the near object increases in blur should reproduce the issue.
4. Nanite is heavily recommended to be enabled on the objects. It is not required, but it seems to induce the issue more readily.

Expected: DoF is smoothly increasing in blur
Actual: After a period of normal near-field blurring, the periphery of the screen will begin to exhibit block artefacts in the DoF.