RFR: 8336258: Document the behavior of 'exclude' and 'compileonly' with respect to inlining

[Volker Simonis]

The long-standing behavior of the `exclude` CompileCommand is to also apply to inlined versions of a method. On the other hand, the `compileonly` CompileCommand only affects top-level compilations of a method and not its inlining behavior.

The rational behind this decision is that `exclude` is intended to be used in production to workaround compiler crashes or bad compilations for certain methods and in these scenarios it usually doesn't matter if a "bad" method is getting compiled on the top level or if it gets inlined into another compilation unit.

The "inconsistent inlining behavior with CompileOnly" thread on hotspot-compiler-dev discusses this behavior (see [1]). The answer [2] specifically describes this long-standing behavior.

I think it would be good to document this behavior in the output of `-XX:CompileCommand=help`

[1] https://mail.openjdk.org/pipermail/hotspot-compiler-dev/2016-June/thread.html#23575
[2] https://mail.openjdk.org/pipermail/hotspot-compiler-dev/2016-June/023583.html

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Commit messages:
 - 8336258: Document the behavior of 'exclude' and 'compileonly' with respect to inlining

Changes: https://git.openjdk.org/jdk/pull/20142/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20142&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8336258
  Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/20142.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20142/head:pull/20142

PR: https://git.openjdk.org/jdk/pull/20142