etinquis

Results 5 issues of etinquis

#393 with the switch-case indentation addressed

Runs on the emulator with veldrid-spirv updated with binaries from https://github.com/mellinoe/veldrid-spirv/pull/19. ![image](https://user-images.githubusercontent.com/579018/149578611-b0f1de56-24fb-416c-89b0-35f8a642e380.png) ![image](https://user-images.githubusercontent.com/579018/149579728-570aef67-8a8b-466e-a453-075ebf2651cf.png) Emulator fails the following tests: - OpenGLESRenderTests.WriteFragmentDepth (CopyRoundabout InvalidEnum) - OpenGLESTextureTests.FormatCoverage_CopyThenRead - R16_G16_B16_A16_SInt - R16_G16_B16_A16_SNorm - R16_G16_B16_A16_UInt...

* adds TargetVersion to CrossCompileInfo so that the caller can control the target compilation version (if 0 is passed, the behavior is as before) * adds targetVersion param to SpirvCompilation.CompileCompute/CompileVertexFragment...

Sample is based on https://github.com/Nadrin/PBR/. Yet to do: - [ ] Check that existing samples are running properly - [ ] Run through asset ProcessorFormats to make sure they're necessary...