[8u] Request for approval and review: 8139150: ClassVerifier frees exception message while it's still in use

[Tobias Hartmann]

Hi,

please approve and review the following backport to 8u.

https://bugs.openjdk.java.net/browse/JDK-8139150
http://cr.openjdk.java.net/~thartmann/8139150/webrev.00/
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/926d9bae67d3

Nightly testing showed no problems. The change applies cleanly to 8u.

Thanks,
Tobias