[SYCL] Force use of BE selected in LIT.

SYCL/Basic/context_platforms.cpp

@@ -1,5 +1,5 @@
 // RUN: %clangxx -fsycl %s -o %t.out
-// RUN: %t.out
+// RUN: env SYCL_DEVICE_FILTER=%sycl_be %t.out
 #include <CL/sycl.hpp>
 #include <iostream>
 

SYCL/Basic/get_backend.cpp

@@ -1,5 +1,5 @@
 // RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
-// RUN: %t.out
+// RUN: env SYCL_DEVICE_FILTER=%sycl_be %t.out
 //
 //==----------------- get_backend.cpp ------------------------==//
 // This is a test of get_backend().

SYCL/Basic/query_emulate_subdevice.cpp

@@ -2,5 +2,5 @@
 // RUN: env CreateMultipleSubDevices=2 EnableTimestampPacket=1 \
 // RUN: NEOReadDebugKeys=1 SYCL_DEVICE_FILTER="gpu" %t.out
 
-// UNSUPPORTED: gpu-intel-dg1
+// UNSUPPORTED: gpu-intel-dg1,cuda
 #include "query.hpp"

SYCL/Plugin/sycl-ls-gpu-default-any.cpp

@@ -18,3 +18,6 @@
 
 // This test checks that a valid GPU is returned by sycl-ls by default if one
 // is present.
+// The test crashed on CUDA CI machines with the latest OpenCL GPU RT
+// (21.19.19792).
+// UNSUPPORTED: cuda

SYCL/Plugin/sycl-ls.cpp

@@ -9,3 +9,6 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
+// The test crashed on CUDA CI machines with the latest OpenCL GPU RT
+// (21.19.19792).
+// UNSUPPORTED: cuda

SYCL/Scheduler/MultipleDevices.cpp

@@ -1,5 +1,5 @@
 // RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
-// RUN: %t.out
+// RUN: env SYCL_DEVICE_FILTER=%sycl_be %t.out
 
 //===- MultipleDevices.cpp - Test checking multi-device execution --------===//
 //