[foreign-jextract] RFR: 8252247: regenerate jdk.internal.clang.libclang sources using jextract [v2]

[Athijegannathan Sundararajan]

> Regenerated libclang classes and manually adjusted as documented.

Athijegannathan Sundararajan has updated the pull request with a new target base due to a merge or a rebase. The pull
request now contains two commits:

 - Adding default constructor to JextractToolProvider to take care of javac lint issue.
 - 8252247: regenerate jdk.internal.clang.libclang sources using jextract

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Changes: https://git.openjdk.java.net/panama-foreign/pull/290/files
 Webrev: https://webrevs.openjdk.java.net/panama-foreign/290/webrev.01
  Stats: 20558 lines in 15 files changed: 13916 ins; 5718 del; 924 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/290.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/290/head:pull/290

PR: https://git.openjdk.java.net/panama-foreign/pull/290