RFR: 8212794 IBM-964 and IBM-29626C are required for AIX default charset

[Ichiroh Takiguchi]

Hello.

Could you review the fix ?

Bug:    https://bugs.openjdk.java.net/browse/JDK-8212794
Change: https://cr.openjdk.java.net/~itakiguchi/8212794/webrev.00/

I'd like to obtain a sponsor for this issue.


IBM964 charset and IBM29626C charset are required for default charset
on AIX zh_TW and ja_JP locale.
OpenJDK already has IBM964, but it could not be configured for default 
charset.
IBM29626C is new one.
(IBM33722 extends IBM29626C class)

I knew IBM charsets would need to move to somewhere.
The discussion was started by "Adding new IBM extended charsets". [1]
But it's related default charset issue.
Please put them inside of OpenJDK.

About IBM964,
Bhaktavatsal started the discussion [2].
Sherman said that [3]
   the new model (open/make/data/charetmapping), instead of hard-coding 
the map
   into the source code.

This fix only has small sized hard-coded mapping,
IBM964/IBM29626C/IBM33722 refer other charsets conversion table
which are using the new model.
And class file is smaller then before.
Still I used SimpleEUCEncoder class because it's stable.
I think we may re-write it by IBM charsets renewal.

Thanks,
Ichiroh Takiguchi
IBM Japan, Ltd.

[1] 
http://mail.openjdk.java.net/pipermail/core-libs-dev/2018-July/054248.html
[2] 
http://mail.openjdk.java.net/pipermail/core-libs-dev/2018-May/053050.html
[3] 
http://mail.openjdk.java.net/pipermail/core-libs-dev/2018-May/053096.html