RFR: JDK-8224788: jpackage fails on OS X when using --runtime-image

[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).

JDK-8224788: jpackage fails on OS X when using --runtime-image

[1] https://bugs.openjdk.java.net/browse/JDK-8224788

[2] http://cr.openjdk.java.net/~herrick/8224788/webrev.01/

/Andy