RFR: 8303884: jlink --add-options plugin does not allow GNU style options to be provided [v4]

[Henry Jen]

> Improving option value handling to support passing argument value starts with "--".
> 
> Before the fix, in following example, --add-modules will be considered as another option for JLink instead of argument value for --add-options.
> --add-options --add-modules=jdk.incubator.concurrent
> --add-options=--add-modules=jdk.incubator.concurrent
> 
> will cause JLink to report
> Error: no value given for --add-options
> as --add-modules is considered another option for JLink.
> 
> After the fix, by using = will ensure the value is properly handled as argument value
> --add-options=--add-modules=jdk.incubator.concurrent

Henry Jen has updated the pull request incrementally with one additional commit since the last revision:

  Use different error message for ambiguous gnu-style options as value

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22526/files
  - new: https://git.openjdk.org/jdk/pull/22526/files/7060e47f..76ce4472

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22526&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22526&range=02-03

  Stats: 3 lines in 3 files changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/22526.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22526/head:pull/22526

PR: https://git.openjdk.org/jdk/pull/22526