Add intern support to analyzer

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

 library java.engine;
 
+import 'interner.dart';
 import 'java_core.dart';
 
 /**
  * A predicate is a one-argument function that returns a boolean value.
  */
 typedef bool Predicate<E>(E argument);
 
 class StringUtilities {
   static const String EMPTY = '';
   static const List<String> EMPTY_ARRAY = const <String>[];
-  static String intern(String s) => s;
+
+  static Interner INTERNER = new NullInterner();
+
+  static String intern(String string) => INTERNER.intern(string);
   static bool isTagName(String s) {
     if (s == null || s.length == 0) {
       return false;
     }
     int sz = s.length;
     for (int i = 0; i < sz; i++) {
       int c = s.codeUnitAt(i);
       if (!Character.isLetter(c)) {
         if (i == 0) {
           return false;
@@ skipping 286 matching lines @@
       if (cause != null) {
         buffer.write('Caused by ');
         cause._writeOn(buffer);
       }
     } else {
       buffer.writeln(exception.toString());
       buffer.writeln(stackTrace.toString());
     }
   }
 }