RFR: 8268435: (ch) ChannelInputStream could override readAllBytes [v2]

[Brian Burkhalter]

> This change would override `readAllBytes()` and `readNBytes(int)` in `ChannelInputStream` thereby improving performance for all but smaller streams.

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

  8268435: Use instanceof pattern matching

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5645/files
  - new: https://git.openjdk.java.net/jdk/pull/5645/files/11baa379..ca188f03

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5645&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5645&range=00-01

  Stats: 21 lines in 2 files changed: 5 ins; 5 del; 11 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5645.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5645/head:pull/5645

PR: https://git.openjdk.java.net/jdk/pull/5645