RFR: 8296420: javac has long lines in its command-line help [v2]

[Archie L. Cobbs]

> The issue states that the output of `javac --help` and `javac --help-extra` should not overflow 80 columns.
> 
> This patch updates `javac.properties` to add newlines, etc. to address this issue, and adds a regression test.

Archie L. Cobbs has updated the pull request incrementally with one additional commit since the last revision:

  Replace "whether or not" with just "whether".

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13329/files
  - new: https://git.openjdk.org/jdk/pull/13329/files/37ccfd06..cfc2c3da

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13329&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13329&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/13329.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13329/head:pull/13329

PR: https://git.openjdk.org/jdk/pull/13329