RFR: 8323605: Java source launcher should not require `--source ...` to enable preview [v6]

[Christian Stein]

> Please review this PR targeting the source launcher that instead of throwing an error reading _"--enable-preview must be used with --source"_ adds the required compiler arguments on-the-fly.
> 
> The add arguments are `--release` and `feature`, with `feature` being the release feature number of the current Java runtime as acquired by `Runtime.version().feature()`.

Christian Stein has updated the pull request incrementally with one additional commit since the last revision:

  Remove superfluous backticks

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Changes:
  - all: https://git.openjdk.org/jdk/pull/17731/files
  - new: https://git.openjdk.org/jdk/pull/17731/files/a82e4fe3..dccb064e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17731&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17731&range=04-05

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17731.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17731/head:pull/17731

PR: https://git.openjdk.org/jdk/pull/17731