split dom frontier handling stuff out to its own DominanceFrontier header,
so that Dominators.h is *just* domtree. Also prune #includes a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122714 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/PostDominators.cpp b/lib/Analysis/PostDominators.cpp
index e648822..3f0deab 100644
--- a/lib/Analysis/PostDominators.cpp
+++ b/lib/Analysis/PostDominators.cpp
@@ -19,6 +19,7 @@
#include "llvm/Support/Debug.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SetOperations.h"
+#include "llvm/Assembly/Writer.h"
#include "llvm/Analysis/DominatorInternals.h"
using namespace llvm;