[8u] RFR: 8066652: Default TimeZone is GMT not local if user.timezone is invalid on Mac OS

[Alex Kashchenko]

Hi,

Please review a parity backport of JDK-8066652:

Bug: https://bugs.openjdk.java.net/browse/JDK-8066652

Original commit: https://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/17a073876794

8u webrev: https://cr.openjdk.java.net/~akasko/jdk8u/8066652/webrev.00/

Only 8u-specific change is that copyright year hunk is skipped.

Testing: checked that added test fails on Mac without the patch and
passes with the patch. Ran jtreg:java/util/TimeZone on Mac and Linux.

-- 
-Alex