LINQ: Unexpected token: name (CSharpEnumerator)

I Use angular-cli to create an angular project, and import linq-es2015. When I typed:

ng build --prod --aot

there was an error: 8ef7c4cbb4dc50.chunk.js from UglifyJs Unexpected token: name (CSharpEnumerator) [0.4cff4e8ef7c4cbb4dc50.chunk.js:872,6]

Here is a DEMO that can reappearance the problem.