RFR: 8230623: Extract command-line help for -Xlint sub-options to new --help-lint [v2]

[Guoxiong Li]

> Hi all,
> 
> This patch splits out the concrete keys of -Xlint into a new option, --help-lint, 
> so that the output of --help-extra is kept clean and concise.
> 
> Thank you for taking the time to review.
> 
> Best Regards.

Guoxiong Li has updated the pull request incrementally with one additional commit since the last revision:

  Remove the content in documentation javac.1

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1758/files
  - new: https://git.openjdk.java.net/jdk/pull/1758/files/b844e8c4..b73d62e6

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1758&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1758&range=00-01

  Stats: 5 lines in 1 file changed: 0 ins; 5 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1758.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1758/head:pull/1758

PR: https://git.openjdk.java.net/jdk/pull/1758