8172307(S): Remove ununsed JVM API JVM_GetModuleByPackageName()

[harold seigel]

Hi,

Please review this JDK-10 change to finish removing the implementation 
of JVM_GetModuleByPackageName(). JDK-8171855 
<https://bugs.openjdk.java.net/browse/JDK-8171855> removed the 
JVM_GetModuleByPackageName() API but not its underlying support in the 
JVM.  This change removes that support because it is no longer needed.

Open Webrevs:

    http://cr.openjdk.java.net/~hseigel/bug_8172307.hs/webrev/

    http://cr.openjdk.java.net/~hseigel/bug_8172307.test/webrev/

JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8172307

The fix was tested with the JCK lang and vm tests, the JTreg hotspot, 
java/io, java/lang, java/util and other tests, the RBT tier2 -tier5 
tests, the colocated and non-colocated NSK tests, and with JPRT.

Thanks, Harold