RFR 8201265: Native memory leak in ClassLoader::add_to_exploded_build_list

[harold seigel]

Hi,

Please review this small fix for JDK-8201265.  The fix deletes the 
native memory before propagating back the exception.

Open Webrev: 
http://cr.openjdk.java.net/~hseigel/bug_8201265/webrev/index.html

JBS Bug:  https://bugs.openjdk.java.net/browse/JDK-8201265

This fix was tested with Mach5 tiers 1 and 2 tests and builds on all 
Mach5 platforms and with tiers 3-5 tests on Linux-x64.

Thanks, Harold