Introduce SPIR-V Backend support in LIT config

Author: VyacheslavLevytskyy

sycl/test-e2e/README.md

@@ -250,6 +250,11 @@ place. No new tests should use these features:
 * **gpu-intel-pvc** - Intel GPU PVC availability;
 * **gpu-intel-pvc-vg** - Intel GPU PVC-VG availability;
 
+### Use the LLVM SPIR-V Backend to generate SPIR-V code
+It's possible to use the LLVM SPIR-V Backend instead of the `llvm-spirv` tool
+to convert LLVM IR to SPIR-V. This feature must be set manually by passing the
+`spirv-backend` parameter to `llvm-lit`.
+
 ### llvm-lit parameters
 
 Following options can be passed to llvm-lit tool through --param option to

sycl/test-e2e/lit.cfg.py

@@ -225,6 +225,8 @@ def check_igc_tag_and_add_feature():
 if lit_config.params.get("enable-perf-tests", False):
     config.available_features.add("enable-perf-tests")
 
+if lit_config.params.get("spirv-backend", False):
+    config.available_features.add("spirv-backend")
 
 # Use this to make sure that any dynamic checks below are done in the build
 # directory and not where the sources are located. This is important for the