[DeviceSanitizer][NFC] Add comments for initialization of LaunchInfo.Data.

[haonanya1]

AsanInterceptor::prepareLaunch has this call, which aligns with msan and tsan.

[haonanya1]

Found the issue when investigate test failure in opencl cpu runtime.

[yingcong-wu]

LGTM, thanks. There is another sync op inside preLaunchKernel, so this one is indeed duplicated and useless.

[haonanya1]

@intel/llvm-gatekeepers, pr is ready to merge. Thank you!

[AllanZyne]

This call is necessary, don't remove it!

[zhaomaosu]

It's better to add comments if it's necessary.

[AllanZyne]

When the kernel is filtered, it's still possible that LaunchInfo is used in kernel code, so the "syncToDevice" here will give it the default value.

To make this PR meaningful, could you help to add a comment to tip others not remove this line?

[yingcong-wu]

It's better to add comments if it's necessary.

I agree. If this is necessary, then the code should be commented for its necessity to avoid such problem.

[yingcong-wu]

Add comment from @AllanZyne and do not remove this line.