[8u] RFR 8225797: [backport] OldObjectSample event creates unexpected amount of checkpoint data

[Denghui Dong]

Hi team,
Please review the following backport.

Original Bug: https://bugs.openjdk.java.net/browse/JDK-8225797
Original patch: https://hg.openjdk.java.net/jdk-updates/jdk11u/rev/2a13c6785ad2
Webrev: http://cr.openjdk.java.net/~ddong/8225797/8u/webrev.00/

Some code has been commented out because those facilities(e.g. Module and Package) is not supported in 8u,
so the original patch can not apply cleanly. Matter of fact, the backport is mostly manual.
I put all reject files in http://cr.openjdk.java.net/~ddong/8225797/rej/

All tests from jdk_jfr are passing after this patch has been applied.

Cheers,
Denghui Dong