RFR: JDK-8304036: Use CommandLine class from shared module [v6]

[Christian Stein]

> This pull request addresses the open ends left by [JDK-8236919](https://bugs.openjdk.org/browse/JDK-8236919):
> - #11272
> 
> Changes:
> - [x] Extend list of targeted exports of `jdk.internal.opt/jdk.internal.opt` to `jdk.compiler` and `jdk.javadoc`
> - [x] Use shared `CommandLine.java` in `jdk.compiler` module
> - [x] Use shared `CommandLine.java` in `jdk.javadoc` module
> - [x] Remove `CommandLine.java` from `jdk.compiler` module

Christian Stein has updated the pull request incrementally with five additional commits since the last revision:

 - Fix hard-coded test
 - Clean up configuration
 - Update test
 - Fix generation of API documentation
 - Add more export directives

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/12997/files
  - new: https://git.openjdk.org/jdk/pull/12997/files/f9a94225..26d14f82

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12997&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12997&range=04-05

  Stats: 18 lines in 7 files changed: 13 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/12997.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/12997/head:pull/12997

PR: https://git.openjdk.org/jdk/pull/12997