[foreign-jextract] RFR: updating samples. changed constants class to use package constructor [v3]

[Athijegannathan Sundararajan]

> fixed to use package private constructors for constants classes. piggybacking to
> include latest samples.

Athijegannathan Sundararajan has updated the pull request incrementally with one additional commit since the last
revision:

  allocate toCString with native scope (libclang sample) per review comment.

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Changes:
  - all: https://git.openjdk.java.net/panama-foreign/pull/292/files
  - new: https://git.openjdk.java.net/panama-foreign/pull/292/files/69ce50de..c5e4af4b

Webrevs:
 - full: https://webrevs.openjdk.java.net/panama-foreign/292/webrev.02
 - incr: https://webrevs.openjdk.java.net/panama-foreign/292/webrev.01-02

  Stats: 53 lines in 2 files changed: 5 ins; 7 del; 41 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/292.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/292/head:pull/292

PR: https://git.openjdk.java.net/panama-foreign/pull/292