Assets with Render in Main Pass disabled show shadow artifacts

This issue was originally reported specifically for Destructibles, but it appears to affect Skeletal Meshes, and static meshes when selected. When "Render in Main Pass" has been disabled skeletal and destructible meshes will show a noticeable artifact with shadows visible through the mesh. Think of it similar to looking through a portal the way this affect looks.

Notes:

• No issue with Static or Movable Light.
• Static Meshes will show the issue when selected and movable, but unselected the issue is no longer visible.
• Stationary Directional Light can remove the issue by setting a Dynamic Shadow Distance, but if using a small value like 1000 - 1500 units you are still within range to see artifacts if the actor is scaled larger.
• Stationary Point Lights, noticeable shadow bias that cannot be adjusted.

Tested in the following builds:

• 4.9.2 CL-2707645
• 4.10.4 CL-2872498
• 4.11.1 CL-2934540
• 4.12 CL-2944947

1. Open any UE4 project
2. Use the Default level with Stationary Light already built
3. Add any Skeletal or Destructible Mesh
4. Select the mesh and in the Details Panel uncheck "Render in Main Pass"

Regression: No

Result: Noticeable shadow artifacts when using Stationary lighting that does not have a far enough Shadow Distance compared to the size of the asset.

Expected: No artifacts visible through the asset when removing from the Main Pass.