-- v6: vkd3d-shader/dxil: Support 16-bit types. vkd3d-shader/spirv: Introduce HALF and UINT16 types for minimum precision. vkd3d-shader/spirv: Introduce a data_type_is_floating_point() helper function. tests/shader-runner: Add tests for minimum-precision constants. tests/shader-runner: Run Shader Model 6 tests in the crossbuild.