RFR: 8315834: Open source several Swing JSpinner related tests

[Tejesh R]

Open source these Swing JSpinner related tests:

javax/swing/JSpinner/4522737/bug4522737.java
javax/swing/JSpinner/4656590/bug4656590.java
javax/swing/JSpinner/4680204/bug4680204.java
javax/swing/JSpinner/4862257/bug4862257.java
javax/swing/JSpinner/5104421/bug5104421.java

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Commit messages:
 - Open sourcing few spinner test

Changes: https://git.openjdk.org/jdk/pull/15678/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15678&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315834
  Stats: 375 lines in 5 files changed: 375 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15678.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15678/head:pull/15678

PR: https://git.openjdk.org/jdk/pull/15678