RFR: 5041655: (ch) FileLock: negative param and overflow issues [v5]

[Brian Burkhalter]

> Add an implementation note to `java.nio.channels.FileLock.overlaps(long,long)` indicating that the method does not check its parameters. Adding such checks would be an incompatible change.

Brian Burkhalter has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:

  5041655: Move size zero handling to file channel impl classes

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7254/files
  - new: https://git.openjdk.java.net/jdk/pull/7254/files/e5d88e23..d1001cc6

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7254&range=04
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7254&range=03-04

  Stats: 3 lines in 1 file changed: 0 ins; 1 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7254.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7254/head:pull/7254

PR: https://git.openjdk.java.net/jdk/pull/7254