RFR: 8268435: (ch) ChannelInputStream could override readAllBytes [v4]

[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: Split up @Tests into multiple, smaller @Tests

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5645/files
  - new: https://git.openjdk.java.net/jdk/pull/5645/files/4ad8e2ab..2b131c08

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5645&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5645&range=02-03

  Stats: 454 lines in 2 files changed: 311 ins; 143 del; 0 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