Rename analyzer-experimental to analyzer_experimental.

pkg/analyzer_experimental/lib/src/generated/java_engine.dart

 library java.engine;
 
 class StringUtilities {
   static List<String> EMPTY_ARRAY = new List(0);
 }
 
 class FileNameUtilities {
   static String getExtension(String fileName) {
     if (fileName == null) {
       return "";
     }
     int index = fileName.lastIndexOf('.');
     if (index >= 0) {
       return fileName.substring(index + 1);
     }
     return "";
   }
 }