Make sure any client of Dominators.h links in Dominators.cpp

Patch by Morten Ofstad


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16987 91177308-0d34-0410-b5e6-96231b3b80d8

lib/VMCore/Dominators.cpp

@@ -298,6 +298,8 @@ bool DominatorSet::runOnFunction(Function &F) {
   return false;
 }
 
+void DominatorSet::stub() {}
+
 namespace llvm {
 static std::ostream &operator<<(std::ostream &o,
                                 const std::set<BasicBlock*> &BBs) {