[llvm] Reapply "[CodeGen] Introduce `MachineDomTreeUpdater`" (#96846) (PR #96851)

[Thurston Dang via llvm-commits]

thurstond wrote:

I think this broke the build, starting at https://lab.llvm.org/buildbot/#/builders/169/builds/490

It's still broken after https://github.com/llvm/llvm-project/commit/aca71efefe3d5907a1128566540d386d2aea8aa9: https://lab.llvm.org/buildbot/#/builders/169/builds/501
```
==1313502==ERROR: AddressSanitizer: use-after-poison on address 0x521000012338 at pc 0x555820abcc52 bp 0x7ffc4ba96960 sp 0x7ffc4ba96958
READ of size 8 at 0x521000012338 thread T0
    #0 0x555820abcc51 in asInt /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/PointerIntPair.h:41:5
    #1 0x555820abcc51 in operator long /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/PointerIntPair.h:45:48
    #2 0x555820abcc51 in getInt /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/PointerIntPair.h:96:57
    #3 0x555820abcc51 in isSentinel /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/ilist_node_base.h:44:52
    #4 0x555820abcc51 in isKnownSentinel /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/ilist_node_base.h:45:41
    #5 0x555820abcc51 in llvm::ilist_iterator<llvm::ilist_detail::node_options<llvm::MachineBasicBlock, true, false, void, false, void>, false, false>::operator*() const /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/ilist_iterator.h:168:5
    #6 0x555820abe4e7 in MachineDomTreeUpdaterTest_LazyUpdateBasicOperations_Test::TestBody() /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/unittests/CodeGen/MachineDomTreeUpdaterTest.cpp:275:3
```

https://github.com/llvm/llvm-project/pull/96851