It is another take on D10084: Faster ensure_valid_reflection() in attempt to fix T88368: Regression: broken normal shading, sharp edges appear on smooth surfaces.. This patch improves both Cycles and Eevee glossy shading by making edges less noticeable on smooth surfaces.

	master	patched
Cycles
Eevee
Cycles
Eevee

There are downsides:

• Faces of a smooth convex surface might look weirdly concave at grazing angles.
• Edges can appear again at roughness 0.1-0.3 and enabled screen-space reflections in Eevee, though they are less noticeable.
• It doesn't fix bump mapping discontinuity as fixed in D9833: Correct bump mapping for smooth normals.