RFR: JDK-8226599 use code coverage results to remove dead code

[Andy Herrick]

Please review the jpackage fix for bug [1] at [2].

This is a fix for the JDK-8200758-branch branch of the open sandbox 
repository (jpackage).


[1] https://bugs.openjdk.java.net/browse/JDK-8226599

[2] http://cr.openjdk.java.net/~herrick/8226599/webrev.03

/Andy