Hacky addition of golden images

This adds a substitution for a golden images directory and a feature check for if it is available.

Author: llvm-beanz

test/lit.cfg.py

@@ -73,3 +73,7 @@
     config.available_features.add("Vulkan")
     if "NVIDIA" in device['Description']:
       config.available_features.add("Vulkan-NV")
+
+if os.path.exists(config.goldenimage_dir):
+  config.substitutions.append(("%goldenimage_dir", config.goldenimage_dir))
+  config.available_features.add("goldenimage")

test/lit.site.cfg.py.in

@@ -10,6 +10,7 @@ config.hlsltest_supports_spirv = @SUPPORTS_SPIRV@
 config.hlsltest_test_clang = @FORCE_CLANG@
 config.hlsltest_test_warp = @FORCE_WARP@
 config.hlsltest_dxc_dir = r"@DXC_DIR@"
+config.goldenimage_dir = r"@GOLDENIMAGE_DIR@"
 
 config.hlsltest_suite = "@suite@"
 config.hlsltest_enable_d3d12 = @TEST_d3d12@