RFR: 7030853: JDK 7 Serializable Swing classes not compatible with JDK 6 [v2]

[Prasanta Sadhukhan]

> The serialized form of the following classes in JDK 7 builds are not compatible with prior versions of Java:
>     javax.swing.text.html.parser.ParserDelegator
>     javax.swing.LayoutComparator
> They need to be declared as not compatible between releases in the API documentation, as is the case for some other serializable Swing classes.
> 
> Since It is widely known that serialized Swing classes are not comptible between major releases, we just didn't add the warning at that couple classes.
> Added the warning..

Prasanta Sadhukhan has updated the pull request incrementally with two additional commits since the last revision:

 - Serialzation warning added in javax.swing package
 - Serialzation warning added in javax.swing package

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11565/files
  - new: https://git.openjdk.org/jdk/pull/11565/files/bbb0dfd0..1994358f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11565&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11565&range=00-01

  Stats: 9 lines in 1 file changed: 8 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/11565.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11565/head:pull/11565

PR: https://git.openjdk.org/jdk/pull/11565