javac --release N does not work for JavaFX modules linked in JDK N+1 runtime

import javafx.application.Application;
public class Testing { public static void main(String... args) {} }

$ javac Testing.java // compile successfully

$ javac --release 8 Testing.java
it results in an error
        Testing.java:1:error: package javafx.application does not exist

It might be reasonable for javac --release 8 to require putting jfxrt.jar from JDK 8 on the classpath since it's target for an older runtime.

I think jdk10/bin/javac --release 9 should support compiling Testing.java.

[1] See http://mail.openjdk.java.net/pipermail/jdk9-dev/2017-October/005993.html