While working on JDK-8369452, I noticed that LocaleEnhanceTest has a test case that checks if Locale.Builder.setLanguageTag(String) throws IllFormedException when passed a tag with multiple extensions. Specifically,

`new BuilderILE() { public void call() { b.setLanguageTag("und-a-xx-yy-b-ww-A-00-11-c-vv"); }};`

In actuality, no test is run because the original code did not pass any arguments to the BuilderILE ctor. When run() is called, no args are available, and run is executed 0 times.

When corrected, the test case actually fails. Either the test case needs to be re-examined, or the behavior of when setLanguageTag is given multiple extensions.