Review Request: JDK-8179950: Custom system class loader using Enum.valueOf in its initialization triggers java.lang.InternalError

[Mandy Chung]

Webrev:
  http://cr.openjdk.java.net/~mchung/jdk9/webrevs/8179950/webrev.00/index.html

This is a regression caused by JDK-8020801 that the initialization of a custom 
system class loader hits a code path that checks if a class is loaded by the 
platform class loader.  Such code path should not call 
ClassLoader::getSystemClassLoader since the system class loader is being 
initialized.

The fix is simple and uses 
jdk.internal.loader.ClassLoaders.platformClassLoader() instead.

Mandy