Extend compiler testing for handling of stream class

[Fznamznon]

We have only one pretty small compiler test for sampler handling https://github.com/intel/llvm/blob/sycl/clang/test/CodeGenSYCL/stream.cpp .
The real stream class implemented in SYCL library is much more complicated than the simple class used in the test.
This test should be extended to check more and we probably need Sema test as well.

[github-actions]

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[Fznamznon]

The testing has been extended.