[PATCH] D8932: Replace custom written DFS walk with depth first iterator

[Daniel Berlin via Phabricator via llvm-commits]

dberlin reclaimed this revision.
dberlin added a comment.
This revision is now accepted and ready to land.

I'm going to reopen this.  The postdom bug in 24415 is much easier to fix if we go with this.
As that bug says, i'm going to make the visited set external, to remove the small slowdown this patch has, and then properly add roots during DFS finding.


https://reviews.llvm.org/D8932