[llvm] [Support] Assert that DomTree nodes share parent (PR #101198)

[via llvm-commits]

dyung wrote:

In the meantime, can we revert this change since there are so many bot failures and that continue to fail so that we can get them back to green?

I will try to work on one of our internal test failures to try and get a repro for the assertion failure that will hopefully be representative if you cannot reproduce the failure from the build bots.

https://github.com/llvm/llvm-project/pull/101198