RFR: 8259943: FileDescriptor.close0 does not handle EINTR

[Brian Burkhalter]

Please review this small change to handle `EINTR` from `close()` in `fileDescriptorClose()`. The function `handleGetLength()` is also changed to handle `EINTR` from `fstat64()` to match other uses of `fstat64()` in the file.

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Commit messages:
 - 8259943: FileDescriptor.close0 does not handle EINTR

Changes: https://git.openjdk.java.net/jdk/pull/2173/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2173&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8259943
  Stats: 10 lines in 1 file changed: 6 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2173.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2173/head:pull/2173

PR: https://git.openjdk.java.net/jdk/pull/2173