[SYCL][NFC] Extend getKernelNamesUsingAssert to support general function names

[jinge90]

Currently, we have getKernelNamesUsingAssert to detect all SPIR kernels which use assert functions via BFS. This PR extend it in 2 points:

1. Support passing a general function name to it for detecting all SPIR kernels using it
2. Support passing a group of special function names for searching SPIR kernels using them.

We may need to check other special function and can easily call it instead of adding a new getKernelNamesUsingXXX.

[maarquitos14]

This LGTM, just wondering if you are planning any follow up patches to make use of this extension? Just to understand why we need this extended.

[github-actions]

@intel/llvm-gatekeepers please consider merging

[aelovikov-intel]

Why manual BFS instead of llvm/include/llvm/Analysis/{CallGraph.h,LazyCallGraph.h}?

And if call graphs above are not suitable, then GraphTraits specialization to enable generic BFS traversal would still be better, IMO.

[jinge90]

Why manual BFS instead of llvm/include/llvm/Analysis/{CallGraph.h,LazyCallGraph.h}?

And if call graphs above are not suitable, then GraphTraits specialization to enable generic BFS traversal would still be better, IMO.

Hi, @aelovikov-intel
I am not the original autor of "traverseCGToFindSPIRKernels" but this function is a small function with fewer than 30 lines of code, I prefer not changing it in this PR.
Thanks very much.