RFR 8214498 : java/util/Locale/bcp47u/SystemPropertyTests.java wrong locale default

[Roger Riggs]

Please review a bug fix for incorrect setting the user.xx.display and 
user.xx.format
system properties when merging the native OS values for locale and the 
command
line overiddes.  The command line argument for user.xx, if set, 
overrides any native
OS settings.

The bug causes a test failure when the OS has a non-US locale configured.
Webrev:
  http://cr.openjdk.java.net/~rriggs/webrev-bcp47u-8214498/

Issue:
  https://bugs.openjdk.java.net/browse/JDK-8214498

Thanks, Roger