--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeStack.java	Fri Feb 02 10:37:48 2018 -0500
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeStack.java	Fri Feb 02 17:28:17 2018 -0800
@@ -74,6 +74,10 @@
         return tos == 0;
     }
 
+    public void clear() {
+        tos = 0;
+    }
+
     @Override
     public String toString() {
         if (tos == 0) {