How to write test requiring a specific locale?

[Weijun Wang]

Hi All

In https://bugs.openjdk.java.net/browse/JDK-8133910, the test tries to 
grep certain text from tool output, but when the default locale is not 
"en_US" it might fail.

I don't want to rewrite the test to check localized text so there are 
only 2 ways:

1. Force the text to run with "en_US". In Unix, seems setting LANG or 
LC_ALL to "en_US.UTF-8" (these are script tests), but it does not work 
on Windows. I can only think of adding "-J-Duser.language=en 
-J-Duser.country=US" into TESTTOOLVMOPTS.

2. Ignore the text when locale is not en_US. The @requires tag does not 
support user.encoding. Shall I check $LANG or $LC_ALL? Should they 
contain "en_US" on most test machines? Or it's "C"?

Thanks
Max