- Removed default shader platform parameter from GetGlobalShaderMap()
- Added an inline overload of GetGlobalShaderMap() that takes a feature level instead, and translates to the correct shader platform
- Cached feature level on FSceneView for faster access
- Cached shader map on FViewInfo for faster access
- Cached featurelevel/shadermap on rendering composition graph execution context, for faster access
Fixed a couple of crashes when switching feature level dynamically
- Needed to allow certain shader permutations to be generated if feature level was ES2, but still on a PC platform. (i.e. hitproxy shaders, and basepass shaders used by editor primitives system)
#codereview Nick.Penwarden
[CL 2275937 by Graeme Thornton in Main branch]
