Revert "[Dominators] Add the DomTreeUpdater class"

Temporary revert because of a failing test on some buildbots.

This reverts commit r336114.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336117 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed