RFR: 7903599: jextract includes extraneous man pages

[Jorn Vernee]

A simple fix which drops the man pages from the generated jlink image. I've also added some other options to strip debug information, and header files, both of which are not needed for the regular non-test runtime image.

The native commands (e.g. `java.exe`) are still needed because we invoke that in the jextract launcher script, so we can't drop those.

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Commit messages:
 - trim down jlink image

Changes: https://git.openjdk.org/jextract/pull/173/files
 Webrev: https://webrevs.openjdk.org/?repo=jextract&pr=173&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903599
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jextract/pull/173.diff
  Fetch: git fetch https://git.openjdk.org/jextract.git pull/173/head:pull/173

PR: https://git.openjdk.org/jextract/pull/173