RFR: JDK-8365400: add JFR event to capture location (if available) of class files loaded

[Larry Cable]

while existing class loading JFR events exist, none of these provide the path (if available) from which a class is loaded/defined, nor are they easily modified to do so from a compatibility standpoint.

therefore this ER/PR adds a simple JFR event that encapsulates a tuple of class and path that can be enabled in order to provide an audit/debug trail of locations (path, if available) from which a particular class is loaded/defined.

this association can be used for various "applications" such as basic auditing etc

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Commit messages:
 - Merge branch 'openjdk:master' into JDK-8365400
 - JDK-8365400: add JFR event to capture location (if available) of class files loaded

Changes: https://git.openjdk.org/jdk/pull/27656/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27656&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8365400
  Stats: 111 lines in 6 files changed: 103 ins; 1 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/27656.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27656/head:pull/27656

PR: https://git.openjdk.org/jdk/pull/27656