make sure to flush the stream after dumping, to make sure it goes out immediately.

llvm-svn: 55288
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index fa73e73..3d620359 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -4982,6 +4982,7 @@
 void SDNode::dump() const { dump(0); }
 void SDNode::dump(const SelectionDAG *G) const {
   print(errs(), G);
+  errs().flush();
 }
 
 void SDNode::print(raw_ostream &OS, const SelectionDAG *G) const {