Move code to update dominator information after basic block is split

from LoopSimplify.cpp to Dominator.cpp


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37689 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/Dominators.h

@@ -302,6 +302,11 @@ public:
   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
     AU.setPreservesAll();
   }
+
+  /// splitBlock
+  /// BB is split and now it has one successor. Update dominator tree to
+  /// reflect this change.
+  void splitBlock(BasicBlock *BB);
 private:
   void calculate(Function& F);
   DomTreeNode *getNodeForBlock(BasicBlock *BB);
@@ -587,6 +592,11 @@ public:
     AU.addRequired<DominatorTree>();
   }
 
+  /// splitBlock
+  /// BB is split and now it has one successor. Update dominace frontier to
+  /// reflect this change.
+  void splitBlock(BasicBlock *BB);
+
 private:
   const DomSetType &calculate(const DominatorTree &DT,
                               const DomTreeNode *Node);