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

[Thurston Dang via llvm-commits]

thurstond wrote:

I think this may have broken the build (https://lab.llvm.org/buildbot/#/builders/169/builds/490/steps/9/logs/stdio):
```
==972762==ERROR: AddressSanitizer: use-after-poison on address 0x521000012338 at pc 0x55fc65d78872 bp 0x7ffd24e98f40 sp 0x7ffd24e98f38
READ of size 8 at 0x521000012338 thread T0
    #0 0x55fc65d78871 in asInt /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/PointerIntPair.h:41:5
    #1 0x55fc65d78871 in operator long /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/PointerIntPair.h:45:48
    #2 0x55fc65d78871 in getInt /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/PointerIntPair.h:96:57
    #3 0x55fc65d78871 in isSentinel /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/ilist_node_base.h:44:52
    #4 0x55fc65d78871 in isKnownSentinel /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/ilist_node_base.h:45:41
    #5 0x55fc65d78871 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 0x55fc65d7772e in MachineDomTreeUpdaterTest_EagerUpdateBasicOperations_Test::TestBody() /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/unittests/CodeGen/MachineDomTreeUpdaterTest.cpp:182:3
```

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