[8u-dev] RFR+RFA (S): 8225137: Clean up remaining CHECK_NULL -> THREAD return issues

[Hohensee, Paul]

Bug: https://bugs.openjdk.java.net/browse/JDK-8225137
Webrev: http://cr.openjdk.java.net/~phh/8225137/webrev.8u.00/

This is a cleanup after the backport of https://bugs.openjdk.java.net/browse/JDK-8064811. The patch avoids having the expansion of CHECK_NULL produce unreachable code. Matched against code in 11u to make sure that no trap handling is required at the modified call sites.

Thanks,

Paul