RFR: 8153858: Clean up needed when obtaining the package name from a fully qualified class name

[Rachel Protacio]

Hello,

Please review this fix, which consolidates/refactors all the instances 
of code parsing fully qualified names and returning the package name. 
Includes gtests for the functions. The gtest framework does not allow 
for passing in a THREAD, so the InstranceKlass functionality is just 
tested by jck tests. Note that the change in method.hpp was a 
compilation error uncovered by my gtest.

Passes hotspot gtests, jck lang and api/java_lang tests, JPRT, and RBT 
hotspot and non-colo tests.

Bug: https://bugs.openjdk.java.net/browse/JDK-8153858
Open webrev: http://cr.openjdk.java.net/~rprotacio/8153858.00/

Thank you,
Rachel