RFR: 8288783: JFR: Error messages are confusing when options conflict in -XX:StartFlightRecording

[Chihiro Ito]

Could I have a review of PR that fixes incorrect error messages regarding of recording.

The current message is very confusing. If a user types jcmd <pid> JFR.start name=abc name=def or java --XX:StartFlightRecording=name=abc,name=def,  the error message says "Duplicates in diagnostic command arguments", but doesn't know what options are duplicated.
Furthermore, if a user specifies two or three duplicate parameters, the same logs will be output.

It should say follows,
Option name can only be specified once with starting flight recording
Options name and disk can only be specified once with starting flight recording
Options name, disk and maxage can only be specified once with starting flight recording
This problem affects --XX:StartFlightRecording, jcmd JFR.start, JFR.stop, JFR.dump, JFR.check, and MBean.

For other than start, the output is as follows, (example of dump)
Option name can only be specified once with dumping flight recording

Testing: jdk/jdk/jfr

Thanks
Chihiro

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Commit messages:
 - modify whitespace from windows to linux
 - modify copyright
 - Modify log message and test case
 - JDK-8288783 Initial

Changes: https://git.openjdk.org/jdk/pull/9302/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9302&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8288783
  Stats: 442 lines in 10 files changed: 431 ins; 2 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/9302.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9302/head:pull/9302

PR: https://git.openjdk.org/jdk/pull/9302