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