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 "";
-  }
-}