Use sycl.hpp workaround only if compiler doesn't have it

Author: romanovvlad

SYCL/lit.cfg.py

@@ -188,10 +188,22 @@
 else:
     arch_flag = ""
 
-# extra_include points to sycl/sycl.hpp location to workaround compiler
-# versions which supports only CL/sycl.hpp
-config.substitutions.append( ('%clangxx', ' '+ config.dpcpp_compiler + ' ' + config.cxx_flags + ' ' + arch_flag + ' ' + ( "/I" if cl_options else "-I") + config.extra_include ) )
-config.substitutions.append( ('%clang', ' ' + config.dpcpp_compiler + ' ' + config.c_flags + ( "/I" if cl_options else "-I") + config.extra_include ) )
+# Add an extra include directory which points to a fake sycl/sycl.hpp (which just points to CL/sycl.hpp)
+# location to workaround compiler versions which do not provide this header
+check_sycl_hpp_file='sycl_hpp_include.cpp'
+with open(check_sycl_hpp_file, 'w') as fp:
+    fp.write('#include <sycl/sycl.hpp>\n')
+    fp.write('int main() {}')
+
+extra_sycl_include = ""
+sycl_hpp_available = subprocess.getstatusoutput(config.dpcpp_compiler+' -fsycl  ' + check_sycl_hpp_file)
+if sp[0] != 0:
+    extra_sycl_include = " " + ("/I" if cl_options else "-I") + config.extra_include
+
+
+config.substitutions.append( ('%clangxx', ' '+ config.dpcpp_compiler + ' ' + config.cxx_flags + ' ' + arch_flag + extra_sycl_include) )
+config.substitutions.append( ('%clang', ' ' + config.dpcpp_compiler + ' ' + config.c_flags + extra_sycl_include) )
+
 config.substitutions.append( ('%threads_lib', config.sycl_threads_lib) )
 
 # Configure device-specific substitutions based on availability of corresponding