[jdk17u] RFR: 8140241: (fc) Data transfer from FileChannel to itself causes hang in case of overlap

[Alex Kasko]

Clean backport of a Mac-specific fix.

Additional testing:

 - [x] checked that added test passes on Mac with this patch. Was unable to reproduce the issue (in virtualized env) without the patch.
 - [x] ran jtreg:jdk/java/nio/channels/FileChannel/ on Mac, Linux and Windows

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Commit messages:
 - Backport 428d51694f56788f89e8df100a74cbadd369ffa6

Changes: https://git.openjdk.java.net/jdk17u/pull/292/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=292&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8140241
  Stats: 167 lines in 6 files changed: 160 ins; 0 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/292.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/292/head:pull/292

PR: https://git.openjdk.java.net/jdk17u/pull/292