RFR: 8287580: (se) CancelledKeyException during channel registration [v4]

[Brian Burkhalter]

> Ignore `CancelledKeyException` during registration.

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8287580: Add CancelDuringRegister test

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Changes:
  - all: https://git.openjdk.org/jdk/pull/8978/files
  - new: https://git.openjdk.org/jdk/pull/8978/files/98bcd22e..85ebbbb6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=8978&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=8978&range=02-03

  Stats: 68 lines in 1 file changed: 68 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/8978.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/8978/head:pull/8978

PR: https://git.openjdk.org/jdk/pull/8978