[foreign-jextract] RFR: 8274280: regenarate libclang binding in jextract module

[Athijegannathan Sundararajan]

Moved CLayouts out of the generated code package. Except for libName & copyright header, no changes to the jextract generated code now.

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Commit messages:
 - 8274280: regenarate libclang binding in jextract module

Changes: https://git.openjdk.java.net/panama-foreign/pull/580/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=580&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274280
  Stats: 764 lines in 32 files changed: 15 ins; 150 del; 599 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/580.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/580/head:pull/580

PR: https://git.openjdk.java.net/panama-foreign/pull/580