[SYCL] Ignore backend warning in discard event test (intel#1050)

The CUDA backend may return a warning in memory prefetch with certain
options. Since that does not affect the discard event test we should not
fail when that happens. These changes allow the warning in the expected
output.

Signed-off-by: Larsen, Steffen <[email protected]>

Author: steffenlarsen

SYCL/DiscardEvents/discard_events_usm_ooo_queue.cpp

@@ -12,6 +12,10 @@
 // The test checks that the last parameter is not `nullptr` for all PI calls
 // that should discard events.
 // {{0|0000000000000000}} is required for various output on Linux and Windows.
+// NOTE: piextUSMEnqueuePrefetch in the CUDA backend may return a warning
+//       result on Windows with error-code -996
+//       (PI_ERROR_PLUGIN_SPECIFIC_ERROR). Since it is a warning it is safe to
+//       ignore for this test.
 //
 // Everything that follows TestQueueOperations()
 // CHECK: ---> piextUSMEnqueueMemset(
@@ -39,7 +43,7 @@
 // CHECK: ---> piextUSMEnqueuePrefetch(
 // CHECK:        pi_event * :
 // CHECK-NOT:        pi_event * : {{0|0000000000000000}}[ nullptr ]
-// CHECK: --->  pi_result : PI_SUCCESS
+// CHECK: --->  pi_result : {{PI_SUCCESS|-996}}
 //
 // CHECK: ---> piextUSMEnqueueMemAdvise(
 // CHECK-NOT:        pi_event * : {{0|0000000000000000}}[ nullptr ]
@@ -96,7 +100,7 @@
 // CHECK: ---> piextUSMEnqueuePrefetch(
 // CHECK:        pi_event * :
 // CHECK-NOT:        pi_event * : {{0|0000000000000000}}[ nullptr ]
-// CHECK: --->  pi_result : PI_SUCCESS
+// CHECK: --->  pi_result : {{PI_SUCCESS|-996}}
 //
 // CHECK: ---> piextUSMEnqueueMemAdvise(
 // CHECK-NOT:        pi_event * : {{0|0000000000000000}}[ nullptr ]