[llvm] [Support] Use bump ptr allocator for domtree nodes (PR #102516)

[Alexis Engelke via llvm-commits]

aengelke wrote:

That turns out to be just an oversight from me. :)

http://llvm-compile-time-tracker.com/compare.php?from=fbb0619fe2acea4ac8764d13b754505ed8f1b578&to=0c87620cab3310dd0034448733c2630c6e9d13c5&stat=max-rss&linkStats=true

https://github.com/llvm/llvm-project/pull/102516