RFR: 8259343: [macOS] Update JNI error handling in Cocoa code.

[Phil Race]

Proposed updates to JNI error handling.

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Commit messages:
 - 8259343: [macOS] Update JNI error handling in Cocoa code.
 - 8259343: [macOS] Update JNI error handling in Cocoa code.

Changes: https://git.openjdk.java.net/jdk/pull/1967/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1967&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8259343
  Stats: 73 lines in 8 files changed: 58 ins; 1 del; 14 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1967.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1967/head:pull/1967

PR: https://git.openjdk.java.net/jdk/pull/1967