RFR: 8233451: (fs) Files.newInputStream() cannot be used with character special files [v2]

[Brian Burkhalter]

> Add `isOther` and `available` methods to `FileChannelImpl` and the interfaces to native code and use these in `ChannelInputStream` to work around cases where a wrapped `FileChannelImpl` is not really seekable.

Brian Burkhalter has updated the pull request incrementally with two additional commits since the last revision:

 - 8233451: Remove use of handleAvailable() (Windows)
 - 8233451: Remove use of handleAvailable() (UNIX)

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/21508/files
  - new: https://git.openjdk.org/jdk/pull/21508/files/235182fb..51df5d81

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21508&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21508&range=00-01

  Stats: 53 lines in 5 files changed: 41 ins; 1 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/21508.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21508/head:pull/21508

PR: https://git.openjdk.org/jdk/pull/21508