RFR: 7903158: jextract crashes due to name clash with pointer to function typedefs [v3]

[Athijegannathan Sundararajan]

> suffixing $ like it is done already for exception variable in the same source file. Piggybacking to remove unused jtreg header is another test

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

  restored test comment of Test7903148

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Changes:
  - all: https://git.openjdk.java.net/jextract/pull/21/files
  - new: https://git.openjdk.java.net/jextract/pull/21/files/a224637e..d33f4027

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jextract&pr=21&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jextract&pr=21&range=01-02

  Stats: 8 lines in 1 file changed: 8 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jextract/pull/21.diff
  Fetch: git fetch https://git.openjdk.java.net/jextract pull/21/head:pull/21

PR: https://git.openjdk.java.net/jextract/pull/21