RFR: 7903181: port jextract for foreign-preview changes

[Athijegannathan Sundararajan]

7903181: port jextract for foreign-preview changes

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Commit messages:
 - removed trailing whitespace in TestBlas.java, TestLapack.java and GitClone.java
 - Merge branch 'master' into foreign-preview
 - 7903197: add a build step to create jmod file for jextract module
 - fixed compilesource.sh of libffmpeg sample with correct include path
 - fixed libffmpeg for foreign-preview.
 - 7903190: jextract runtime helper issues
 - 7903187: jextract should support --version option
 - Adding jdk.zipfs to root modules of jextract jdk image so that --enable-preview
 - simplified libjimage sample. deleted dlfcn extract as it ia not used.
 - removed unnecessary 'allocator' variable in many places. Using session instead for allocation.
 - ... and 5 more: https://git.openjdk.java.net/jextract/compare/e9906418...4f0d0b13

Changes: https://git.openjdk.java.net/jextract/pull/35/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jextract&pr=35&range=00
  Issue: https://bugs.openjdk.java.net/browse/CODETOOLS-7903181
  Stats: 2245 lines in 178 files changed: 70 ins; 1409 del; 766 mod
  Patch: https://git.openjdk.java.net/jextract/pull/35.diff
  Fetch: git fetch https://git.openjdk.java.net/jextract pull/35/head:pull/35

PR: https://git.openjdk.java.net/jextract/pull/35