RFR: 7903731: Jextract should support macOS frameworks [v3]

[Nizar Benalla]

> Read the JBS issue for more detail.
> 
> This patch adds two new mac specific options, to make it easier to use frameworks and remove the need of a `compile_flags.txt` file. An exception is thrown if those options are used from an other platform, the error message is inspired from `jpackage`

Nizar Benalla has updated the pull request incrementally with one additional commit since the last revision:

  use consistent spacing

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

Changes:
  - all: https://git.openjdk.org/jextract/pull/268/files
  - new: https://git.openjdk.org/jextract/pull/268/files/aad02674..9ce83f36

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jextract&pr=268&range=02
 - incr: https://webrevs.openjdk.org/?repo=jextract&pr=268&range=01-02

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jextract/pull/268.diff
  Fetch: git fetch https://git.openjdk.org/jextract.git pull/268/head:pull/268

PR: https://git.openjdk.org/jextract/pull/268