[SYCL] Test bfloat16 devicelib with dlopen/dlclose

[jinge90]

Add test to cover bfloat16 devicelib usage in dlopen/dlclose scenario.

[jinge90]

Hi, @steffenlarsen and @jopperm
Could you help review this PR? This is a follow-up of #17461 to add corresponding test.

[jinge90]

Hi, @intel/llvm-gatekeepers
Could you help merge this PR?
Thanks very much.

[uditagarwal97]

@jinge90 Can you add a test or augment existing one to also test dlopen/dlclose with image compression enabled (--offload-compress)? The code path for handling compressed BF16 devicelibs is different so, it would be a good idea to also test that with explicit dlopen/dlclose

[jinge90]

@jinge90 Can you add a test or augment existing one to also test dlopen/dlclose with image compression enabled (--offload-compress)? The code path for handling compressed BF16 devicelibs is different so, it would be a good idea to also test that with explicit dlopen/dlclose

Hi, @uditagarwal97
I will create a new PR to cover --offload-compress.
Thanks very much.