[11u] Plan to backport 8184193(JFR Streaming) to jdk11u

[Denghui Dong]

Hi team,
  Currently, the status of JET 349: JFR streaming is integrated.
This feature is useful for continuous monitoring, can provide the
monitoring system with more detailed information. 
  jdk-11u is a LTS version, and I think 11u will become the mainstream
version in the next few years, so I plan to backport JFR streaming to 11u.

  The backport for 8184193 requires several other changes as follows to be backported as
well:
  - 8225797: OldObjectSample event creates unexpected amount of checkpoint data
    RFR for 8225797 has been created by Jaroslav.(https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2019-November/002115.html)
so my webrev is based on it.

  - 8231081: TestMetadataRetention fails due to missing symbol id
    Need to do some manual adjustments, because 8209301 (JVM rename is_anonymous, host_klass to unsafe specific terminology ahead of Unsafe.defineAnonymousClass deprecation) has not been ported to 11u,
    and I think it's not necessary.

  - 8230400: Missing constant pool entry for a method in stacktrace
    Need to do some manual adjustments, because of some different code structures, such as the different name of JfrStump in jfrTypeSetUtils.hpp
 
Bug: https://bugs.openjdk.java.net/browse/JDK-8226511
Webrev: http://cr.openjdk.java.net/~ddong/8226511/webrev.00/

   What's your comment?

Thanks
Denghui Dong