RFR: 8307478: Implementation of Prepare to Restrict The Dynamic Loading of Agents [v6]

[Alan Bateman]

> This is the implementation for JEP 451. There are two parts to this:
> 
> 1. A multi-line warning is printed when a JVM TI or Java agent is loaded into a running VM. For JVM TI, the message is printed to stderr from JvmtiAgent::load. For Java agents, it is printed to System.err (as that may be redirected) in the JPLIS (j.l.instrumentation) implementation. This part includes an update to the JVM TI spec and API docs to require the warning.
> 
> 2. If running with -Djdk.instrument.traceUsage or -Djdk.instrument.traceUsage=true, the calls to the Instrumentation API print a trace message and stack trace.
> 
> Testing: tier1-6

Alan Bateman has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 14 additional commits since the last revision:

 - Allow for warning to be skipped when same agent loaded a second/subsequent time
 - Merge
 - Tweak javadoc, update test to use more test infra
 - Merge
 - Merge
 - Refresh package description
 - Merge
 - Tweak docs
 - Merge
 - Draft docs changes
 - ... and 4 more: https://git.openjdk.org/jdk/compare/6a2d218d...a6d3c23c

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13899/files
  - new: https://git.openjdk.org/jdk/pull/13899/files/87022831..a6d3c23c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13899&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13899&range=04-05

  Stats: 25585 lines in 483 files changed: 20080 ins; 2465 del; 3040 mod
  Patch: https://git.openjdk.org/jdk/pull/13899.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13899/head:pull/13899

PR: https://git.openjdk.org/jdk/pull/13899