[jdk8u-dev] RFR: 8154043: Fields not reachable anymore by tab-key, because of new tabbing behaviour of radio button groups.

[ktakakuri]

This is a backport of JDK-8154043: Fields not reachable anymore by tab-key, because of new tabbing behaviour of radio button groups.

Applying the JDK-8154043 fix as is will result in a regression of JDK-8182577.
The fix of JDK-8182577 adds an interface for JDK10, therefore this fix cannot be backported simply for JDK8u.
So, I propose to judge the buttonModel is an instance of DefaultButtonModel.

Testing:
java/awt
javax/swing
ButtonGroupLayoutTraversalTest.java
bug8033699.java
DefaultButtonModelCrashTest.java
on Windows x86_64

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Commit messages:
 - Chmod ButtonGroupLayoutTraversalTest
 - Chmod DefaultButtonModelCrashTest
 - Fix the copyright year
 - Backport f3abf05b31893b9a066a436e2c4a587f8899ab10
 - Backport 8d81ec63b2bafc431cbb8572a3e45e76580ab46f

Changes: https://git.openjdk.org/jdk8u-dev/pull/285/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=285&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8154043
  Stats: 305 lines in 5 files changed: 270 ins; 15 del; 20 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/285.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/285/head:pull/285

PR: https://git.openjdk.org/jdk8u-dev/pull/285