[clang] Revert "[clang][dataflow] Expose simple access to child StorageLocation presence." (PR #145710)

[Samira Bakon via cfe-commits]

bazuzi wrote:

This reverts a simple change added <24 hours ago and reverting has been discussed directly with original change reviewers. Merging without additional review.

https://github.com/llvm/llvm-project/pull/145710