[SYCL] Refactor processing of parallel_for_work_group constructs

[premanandrao]

Our processing of parallel_for_work_group was fetching the lambda function by walking the
caller statements. We now fetch the equivalent information from the GetSYCLKernelObjType
function. This refactoring also removes some validation which are no longer necessary.

[elizabethandrews]

Did you mean to remove the tests you had in your previous commit? What happens when those invalid cases are encountered now?

[premanandrao]

Did you mean to remove the tests you had in your previous commit? What happens when those invalid cases are encountered now?

I did mean to remove. They continue to get the same diagnostics as they did before, but without the assertion about the missing Lambda.

[elizabethandrews]

Did you mean to remove the tests you had in your previous commit? What happens when those invalid cases are encountered now?

I did mean to remove. They continue to get the same diagnostics as they did before, but without the assertion about the missing Lambda.

Should we test the diagnostics since this is technically a functionality change i.e. your refactor fixes a crash.

[premanandrao]

Should we test the diagnostics since this is technically a functionality change i.e. your refactor fixes a crash.

I don't feel strongly about it. But if you prefer, I can add a simple test back.

[elizabethandrews]

Should we test the diagnostics since this is technically a functionality change i.e. your refactor fixes a crash.

I don't feel strongly about it. But if you prefer, I can add a simple test back.

I think that would be better since any functionality change should technically be accompanied by a test change.

[premanandrao]

Thanks for the reviews and the merge!