[jdk15u-dev] RFR: 8256810: Incremental rebuild broken on Macosx

[Yuri Nesterenko]

This should be fixed in 15u, too, and after that, fix JDK-8257547

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Commit messages:
 - Backport 4c86e46d75f6703aeab165df9c4068a76786d538

Changes: https://git.openjdk.java.net/jdk15u-dev/pull/33/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk15u-dev&pr=33&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256810
  Stats: 8 lines in 1 file changed: 5 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk15u-dev/pull/33.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk15u-dev pull/33/head:pull/33

PR: https://git.openjdk.java.net/jdk15u-dev/pull/33