RFR: 8278268 - (ch) InputStream returned by Channels.newInputStream should have fast path for FileChannel targets [v10]

[Markus KARG]

> This sub-issue defines the work to be done to implement JDK-8265891 solely for the particular case of FileChannel.transferFrom(ReadableByteChannel), including special treatment of SelectableByteChannel.

Markus KARG has updated the pull request incrementally with five additional commits since the last revision:

 - separate out new tests into TransferTo2.java
   
   Signed-off-by: Markus Karg <markus at headcrashing.eu>
 - Revert "Common implementation for all 2 GB tests"
   
   This reverts commit f8ba3a87221092ab3212732dd77a5d471ad1b13e.
 - Revert "Simplified using checked function"
   
   This reverts commit 4c2930fe71de4e29a779dea74edd9152676751f2.
 - No need to run test twice with same data point
   
   Signed-off-by: Markus Karg <markus at headcrashing.eu>
 - Test cleanup proposed by Lance Andersen
   
   Signed-off-by: Markus Karg <markus at headcrashing.eu>

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6711/files
  - new: https://git.openjdk.java.net/jdk/pull/6711/files/2b72855f..709d258d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6711&range=09
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6711&range=08-09

  Stats: 546 lines in 2 files changed: 422 ins; 57 del; 67 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6711.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6711/head:pull/6711

PR: https://git.openjdk.java.net/jdk/pull/6711