Summary: Use scratch_class to find EMCP methods for breakpoints if the
old methods are still running
See bug for more details. This fix also includes a change to
nmethod::metadata_do() to not walk the _method multiple times (the
_method is added to the metadata section of the nmethod), and an attempt
to help the sweeper clean up these scratch_class instance classes sooner.
Tested with nsk tests, java/lang/instrument tests and jck tests (which
include some jvmti tests).
open webrev at http://cr.openjdk.java.net/~coleenp/8055008/
bug link https://bugs.openjdk.java.net/browse/JDK-8055008
Thanks,
Coleen
