RFR: 8248383: Clarify java.io.Reader.read(char[], ...) behavior for full array [v4]

[Brian Burkhalter]

> Please review this small verbiage change to specify clearly the behavior of `Reader::read(char[] cbuf)` when the length of `cbuf` is zero, and that of `Reader::read(char[] cbuf, int off, int len)` when `len` is zero.

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

  8248383: Convert test ReadIntoZeroLengthArray to TestNG

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1737/files
  - new: https://git.openjdk.java.net/jdk/pull/1737/files/7fbc77f7..ab73f98d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1737&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1737&range=02-03

  Stats: 43 lines in 1 file changed: 21 ins; 7 del; 15 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1737.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1737/head:pull/1737

PR: https://git.openjdk.java.net/jdk/pull/1737