Review Request JDK-8164512: Replace ClassLoader use of finalizer with phantom reference to unload native library

[mandy chung]

Hi David,

Thanks for raising the lazy initialization issue.  The recent version of 
ClassLoader.java in webrev.03 is uploaded in place:
http://cr.openjdk.java.net/~mchung/jdk10/webrevs/8164512/webrev.03/

The native libraries map is now created lazily with synchronization.    
I keep the lazy initialization that will save to create a CHM as many 
custom class loaders don't have native code.  I think it's a good 
saving.   In addition, if we iniitialize the static 
systemNativeLibraries at <clinit> time, it may want to avoid using CHM 
as it changes the class initialization order.

thanks
Mandy