increase compute intensity of kern3 in the test

Author: oleksandr-pavlyk

dpctl/tests/test_sycl_kernel_submit.py

@@ -135,6 +135,11 @@ def test_async_submit():
         "   global unsigned int *arg2)"
         "{"
         "  size_t index = get_global_id(0);"
+        "  size_t i = 0; "
+        "  size_t unused_sum = 0;"
+        "  for (i = 0; i < 4000; i++) { "
+        "       unused_sum += i;"
+        "  } "
         "  res[index] = "
         "      (arg1[index] < arg2[index]) ? arg1[index] : arg2[index];"
         "}"