Review request for JDK-8139435: Make sure CallSiteDescriptor.getLookup is subject to a security check

[Attila Szegedi]

Please review JDK-8139435 "Make sure CallSiteDescriptor.getLookup is subject to a security check" at <http://cr.openjdk.java.net/~attila/8139435/webrev.jdk9> for <https://bugs.openjdk.java.net/browse/JDK-8139435>

Notes:
- webrev also shows a previous issue in the history of some of the files, but the changes for that issue are not in the diffs.
- the mechanism for security checks in this changeset is sound, but it is even further improved by making CallSiteDescriptor into a proper class and internalizing the checks later on (I will be sending that changeset for review separately later).

Thanks,
  Attila.