src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/parser/Parser.java

*** 2763,2772 ****
--- 2763,2777 ----
                  FunctionNode.Kind.NORMAL,
                  functionLine,
                  functionBody);
  
          if (isStatement) {
+             if (isAnonymous) {
+                 appendStatement(new ExpressionStatement(functionLine, functionToken, finish, function));
+                 return function;
+             }
+ 
              // mark ES6 block functions as lexically scoped
              final int     varFlags = (topLevel || !useBlockScope()) ? 0 : VarNode.IS_LET;
              final VarNode varNode  = new VarNode(functionLine, functionToken, finish, name, function, varFlags);
              if (topLevel) {
                  functionDeclarations.add(varNode);