handler_mem_op.cpp and buffer_dev_to_dev.cpp tests fail sporadically on cuda

[fadeeval]

sycl/test/basic_tests/handler/handler_mem_op.cpp and sycl/test/basic_tests/buffer/buffer_dev_to_dev.cpp tests fail sporadically on cuda.

Signed-off-by: Aleksander Fadeev aleksander.fadeev@intel.com

[bader]

sycl/test/basic_tests/buffer/buffer_dev_to_dev.cpp is disabled by #1526.

[bader]

sycl/test/basic_tests/handler/handler_mem_op.cpp is disabled by #1533

[bjoernknafla]

Unchecked yet, but I suspect the following PR (fixing a racecondition when creating buffers before accessing them on device) addresses this issue: #1798

[bader]

Should we enable them back and check?

[bjoernknafla]

I am currently running and rerunning these tests but am not seeing any fails on my local machine. Enabling them seems to be save or will then fail on other machines so it is clear that more investigation is necessary.

I will create PR to re-enable the tests.

[bjoernknafla]

PR to re-enable these LIT tests for CUDA: #1843