[Rev 07] RFR: 6554: Support JFR in OpenJDK 8

[Marcus Hirt]

> This is for OpenJDK 8 implementations that have backported JFR, e.g. Azul's JDK. There is also a backport effort for OpenJDK 8 in general.

The pull request has been updated with 1 additional commit.

-------------

Added commits:
 - 2b237429: Acting on feedback

Changes:
  - all: https://git.openjdk.java.net/jmc/pull/19/files
  - new: https://git.openjdk.java.net/jmc/pull/19/files/4fa515d3..2b237429

Webrevs:
 - full: https://webrevs.openjdk.java.net/jmc/19/webrev.07
 - incr: https://webrevs.openjdk.java.net/jmc/19/webrev.06-07

  Stats: 28 lines in 1 file changed: 9 ins; 0 del; 19 mod
  Patch: https://git.openjdk.java.net/jmc/pull/19.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/19/head:pull/19

PR: https://git.openjdk.java.net/jmc/pull/19