RFR: 8272417: ZGC: fastdebug build crashes when printing ClassLoaderData

[Tongbao Zhang]

Following test fails on fastdebug build with the options: "-XX:+UseZGC -XX:+VerifyAfterGC -Xlog:gc*=trace". It crashes on the unknown claim value of the ClassLoaderData

public class A {
    public static void main(String... args) {
        System.gc();
    }
}

The unknown claim value  of the ClassLoaderData is "ClassLoaderData::_claim_other | ClassLoaderData::_claim_strong" which is introduced by the ZVerifyOopClosure. This patch clears the CLD's claimed marks after the ZGC verification

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Commit messages:
 - 8272417: ZGC: fastdebug build crashes when printing ClassLoaderData

Changes: https://git.openjdk.java.net/jdk/pull/5107/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5107&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8272417
  Stats: 5 lines in 1 file changed: 5 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5107.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5107/head:pull/5107

PR: https://git.openjdk.java.net/jdk/pull/5107