Summary:
Require DominatorTree when requiring/preserving LoopInfo in the old pass manager
BreakCriticalEdges tries to keep LoopInfo and DominatorTree updated if they
exist. However, since commit r321653 and r321805, to update LoopInfo we
must have a DominatorTree, or we will hit an assert.
To fix this we now make a couple of passes that only required/preserved
LoopInfo also require DominatorTree.
This solves PR37334.
Reviewers: eli.friedman, efriedma
Reviewed By: efriedma
Subscribers: efriedma, llvm-commits
Differential Revision: https://reviews.llvm.org/D46829
llvm-svn: 332583