[foreign-jextract] RFR: 8257599: foreign-jextract branch build, test failures

[Athijegannathan Sundararajan]

Mainly CLinker.C_LONGLONG -> CLinker.C_LONG_LONG and Clinker.C_LONGDOUBLE removal changes.

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Commit messages:
 - 8257599: foreign-jextract branch build, test failures

Changes: https://git.openjdk.java.net/panama-foreign/pull/403/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=403&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8257599
  Stats: 72 lines in 15 files changed: 0 ins; 39 del; 33 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/403.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/403/head:pull/403

PR: https://git.openjdk.java.net/panama-foreign/pull/403