RFR: 8267374: macOS: Option+Up/Down Arrow don't traverse to beginning/end of line in JTextArea [v9]

[Prasanta Sadhukhan]

> Unlike in native "Notes" editor where Option+Up/Down traverses to start/end of each line respectively,
> Java does not honour these key combination in editor.
> 
> Added the key combination support by moving the caret to start/end of line and then doing caret up/down a line depending on if we are pressing UP or DOWN key.

Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:

  Restrict one more test for ALTGraph

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9230/files
  - new: https://git.openjdk.org/jdk/pull/9230/files/392b415a..78df4a71

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9230&range=08
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9230&range=07-08

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/9230.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9230/head:pull/9230

PR: https://git.openjdk.org/jdk/pull/9230