[foreign-jextract] RFR: 8265211: Print specific error message when an option parsing error occurs [v2]

[Jorn Vernee]

> Hi,
> 
> This patch makes jextract print a more specific error message when an option parsing error occurs, where currently only the help message is printed.
> 
> For instance, when using an unrecognized option `-o` it will print
> 
> 
> OPTION ERROR: o is not a recognized option
> 
> 
> Or when specifying multiple header files
> 
> 
> OPTION ERROR: Expected 1 header file, not 3
> 
> 
> Thanks,
> Jorn

Jorn Vernee has updated the pull request incrementally with one additional commit since the last revision:

  Print usage and --help hint on option error as well.

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

Changes:
  - all: https://git.openjdk.java.net/panama-foreign/pull/500/files
  - new: https://git.openjdk.java.net/panama-foreign/pull/500/files/77cc4502..b8d56f1e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=500&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=500&range=00-01

  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/500.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/500/head:pull/500

PR: https://git.openjdk.java.net/panama-foreign/pull/500