Remove usage of std::memcmp in bit_cast_test.h

[HPS-1]

Currently, test sycl_cts/bit_cast_test_core uses std::memcmp which is not guaranteed to be supported under SYCL 2020. Thus replacing it with a helper function that implement the functionality of std::memcmp without linking external library

[CLAassistant]

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[bader]

Thus replacing it with memcmp among sycl built-in functions.

I can't find memcmp in SYCL 2020 spec neither. Are you sure that dropping std:: namespace replaces std version with SYCL and not C version? I would add sycl:: to validate that, but assuming that SYCL 2020 doesn't provide memcmp device function this should not work either.

Probably the easiest way is to implement memcpy w/o using external libraries as SYCL-CTS utility function.

[HPS-1]

Thus replacing it with memcmp among sycl built-in functions.

I can't find memcmp in SYCL 2020 spec neither. Are you sure that dropping std:: namespace replaces std version with SYCL and not C version? I would add sycl:: to validate that, but assuming that SYCL 2020 doesn't provide memcmp device function this should not work either.

Probably the easiest way is to implement memcpy w/o using external libraries as SYCL-CTS utility function.

Hi Alexey! Thanks for reviewing this. I've fixed the issue as you suggested. Could you please take a look and let me know if it looks good? Thanks! @bader