[8u-dev] Request for approval for Japanese supplemental era related fixes - 8054214, 8173423, 8177678

[Naoto Sato]

Hello,

Please approve the backport of the fixes for the supplemental Japanese 
era related bugs. The issue-links/changesets/discussions for JDK9 are as 
follows:

https://bugs.openjdk.java.net/browse/JDK-8054214
http://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/21b45d72c6c0
http://mail.openjdk.java.net/pipermail/core-libs-dev/2016-December/045310.html

https://bugs.openjdk.java.net/browse/JDK-8173423
http://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/e0ab92b7360f
http://mail.openjdk.java.net/pipermail/core-libs-dev/2017-January/046150.html

https://bugs.openjdk.java.net/browse/JDK-8177678
http://hg.openjdk.java.net/jdk9/dev/jdk/rev/e685e3197f62
http://mail.openjdk.java.net/pipermail/core-libs-dev/2017-March/046956.html

The proposed webrev is located at:

http://cr.openjdk.java.net/~naoto/8054214.8173423.8177678/webrev.00/

The changes apply cleanly, except the copyright year and test cases that 
are specific to JDK9, which are removed in this request.

Naoto