Created by: Piasy
Summary:
To let BUCK build java 8 sources correctly, we need add rt.jar into javac classpath, otherwise, android_library rule will fail to compile (but java_library compiles successfully).
Test Plan: Build updated code, and tested in demo this repo: https://github.com/Piasy/BuckJava8RetroLambdaDemo, unit test code need to be updated.