Blender Git Loki

Enable displacement for geometry cache

Add bvh for subpatches

Adding a geometry cache

Squashed the following 7 commits:

- Add geometry cache ; geom cache

- Add geometry cache ; geom

- Add geometry cache ; bvh

- Add geometry cache ; mesh

- Add geometry cache ; sync

- Add geometry cache ; subd

- Add geometry cache ; geom bvh

Add basic OpenSubDiv support

Seperate dice and split for subdivision meshes

Add max subdivision setting to subdivision meshes

Fix support for triangles in DiagSplit implementation

Add displacement scale option to displaced meshes

Add preview dice rate for displacement

Change Cycles displacement UI to split column

Set normals properly for subdivision meshes

Migrate away from ccl::SubdMesh for tessellation

Change use subdivision bool to subdivision type enum

Have dicing happen in screen space

Inlining of base node functions in LLVM IR code.

This requires a somewhat hackish stub function to force linking of inlined
functions in the modules, so that clang doesn't just omit them when
producing IR code. Not very nice, but also not directly related to the
actual Blender code.

Fix compile error with WITH_INPUT_HMD disabled

Corrections for WITH_INPUT_HMD

Display HMD vendor name in UserPref HMD device option

And minor cleanup.

Quiet warnings without WITH_OPENHMD

Bring back version patch

Without it building with WITH_OPENHMD disabled will activate an invalid UserPref HMD device item.