[13] RFR: JDK-8221993: Create test to validate package declarations in source files

[Kevin Rushforth]

Please review the following test to check that the package name matches 
the file's location on disk:

https://bugs.openjdk.java.net/browse/JDK-8221993
https://github.com/javafxports/openjdk-jfx/pull/430

-- Kevin