Implementing non-geometry-shader path for rendering stencil shadows,
used by the workbench engine.
Patch also contains a few small modifications to Create-info to ensure
usage of gl_FragDepth is explicitly specified.
This is required for testing of the patch.
Authored by Apple: Michael Parkin-White
Ref T96261
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D16436
9ec20f2ede