Memory types, bitcode, MSL 8/16-bit & spec constants
- Fix memoryTypes order to match Vulkan spec.
- Allow linear images to use host-coherent memory.
- Generate Bitcode in iOS libraries.
- Allow all pipeline attachements to be unused.
- Perform usage checks on 3D images.
- Enhancements to dylib generation script.
- Update to latest SPIRV-Cross version:
- MSL: Support 8 & 16 bit types.
- MSL: Updated spec constant support.