[SYCL] Run the LIT tests using the selected backend

sycl/test/CMakeLists.txt requests which backend to test by passing to
the LIT configuration either

    PARAMS "SYCL_BE=PI_OPENCL"

or

    PARAMS "SYCL_BE=PI_CUDA"

This change passes the backend choice to the test throught its
environment.

Signed-off-by: Andrea Bocci <[email protected]>

Author: fwyzard

sycl/test/lit.cfg.py

@@ -88,7 +88,8 @@
         print("Adding path to opencl-aot tool to PATH")
         os.environ['PATH'] = os.path.pathsep.join((os.getenv('PATH'), config.sycl_tools_dir))
 
-backend=lit_config.params.get('SYCL_BE', "PI_OPENCL")
+backend = lit_config.params.get('SYCL_BE', "PI_OPENCL")
+config.environment['SYCL_BE'] = backend
 
 get_device_count_by_type_path = os.path.join(config.llvm_tools_dir, "get_device_count_by_type")
 
@@ -157,8 +158,6 @@ def getDeviceCount(device_type):
     if platform.system() == "Linux":
         gpu_run_on_linux_substitute = "env SYCL_DEVICE_TYPE=GPU "
         gpu_check_on_linux_substitute = "| FileCheck %s"
-        if cuda:
-            gpu_run_on_linux_substitute += " SYCL_BE=PI_CUDA "
 
 config.substitutions.append( ('%GPU_RUN_PLACEHOLDER',  gpu_run_substitute) )
 config.substitutions.append( ('%GPU_RUN_ON_LINUX_PLACEHOLDER',  gpu_run_on_linux_substitute) )