[8u] RFR 8250665: Wrong translation for the month name of May in ar_JO,LB,SY

[Zhengyu Gu]

I would like to backport this patch to 8u for parity with Oracle 8u281.

The original patch does not apply cleanly, but conflicts are limited on 
copyright years and bug id lines of LocaleDataTest.java, can be easily 
resolved manually.

The original bug: https://bugs.openjdk.java.net/browse/JDK-8250665
The original patch: https://hg.openjdk.java.net/jdk/jdk/rev/9aa999666ccc

8u webrev: http://cr.openjdk.java.net/~zgu/JDK-8250665-8u/webrev.00/

Test:
   LocaleDataTest.java

Thanks,

-Zhengyu