[8u] RFR: 8135322: ConstantPool::release_C_heap_structures not run in some circumstances

[Andreas Eriksson]

Hi,

Please review this backport of 8135322: 
ConstantPool::release_C_heap_structures not run in some circumstances
Bug: https://bugs.openjdk.java.net/browse/JDK-8135322
Webrev: http://cr.openjdk.java.net/~aeriksso/8135322/webrev.jdk8.00

The backport is the same as the JDK 9 version, but the patch didn't 
apply cleanly because the context was different (tty->print_cr("]") 
instead of log->cr() above, and another function below).

Thanks,
Andreas