[13u] RFR: 8212970: TZ database in "vanguard" format support

[Ramanand Patil]

Hi all,
Please review this backport to JDK13 updates:
Bug: https://bugs.openjdk.java.net/browse/JDK-8212970
Webrev: http://cr.openjdk.java.net/~rpatil/8212970/webrev.00/
Original Changeset: https://hg.openjdk.java.net/jdk/jdk/rev/99d2dd7b84a8

The patch from jdk14 was not applied cleanly. Here is the change summary:
	- All the deletions in test/jdk/sun/util/calendar/zi/tzdata and test/jdk/sun/util/calendar/zi/tzdata_jdk are done manually.
	- The original patch(jdk14) had tzdata2019a vanguard format, but since the jdk13u is already patched with tzdata2019b rearguard format, in this patch tzdata files used are from tzdata2019b vanguard format.
Post this backport, it will be easy to backport future tzdata versions starting tzdata2019c(JDK-8231098).

All the related tests including JCK are passed.


Regards,
Ramanand.