SafepointIRVerifier crashed while traversing blocks without a DomTreeNode.
This could happen with a custom pipeline or when some optional passes were skipped by OptBisect.
SafepointIRVerifier is fixed to traverse basic blocks that are reachable from entry. Test are added.
Patch Author: Yevgeny Rouban!
Reviewers: anna, reames, dneilson, DaniilSuchkov, skatkov
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47011
llvm-svn: 333063
Serguei Katkov