add isUser and isGenerated path methods

src/babel/traversal/path/index.js

@@ -125,6 +125,22 @@ export default class TraversalPath {
     return false;
   }
 
+  /**
+   * Check whether this node was a part of the original AST.
+   */
+
+  isUser() {
+    return this.node && !!this.node.loc;
+  }
+
+  /**
+   * Check whether this node was generated by us and not a part of the original AST.
+   */
+
+  isGenerated() {
+    return !this.isUser();
+  }
+
   /**
    * Description
    */