[foreign-jextract] RFR: 8261879: jextract javac compilation errors should not result in OUTPUT_ERROR exit code

[Athijegannathan Sundararajan]

correct exit code is used for javac compilation errors.

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Commit messages:
 - 8261879: jextract javac compilation errors should not result in OUTPUT_ERROR exit code

Changes: https://git.openjdk.java.net/panama-foreign/pull/452/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=452&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8261879
  Stats: 49 lines in 3 files changed: 45 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/452.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/452/head:pull/452

PR: https://git.openjdk.java.net/panama-foreign/pull/452