Backport analyzer-experimental changes to 'resources'.

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

 library java.core;
 
 import "dart:math" as math;
 import "dart:uri";
 import "dart:collection" show ListBase;
 
 class JavaSystem {
   static int currentTimeMillis() {
     return (new DateTime.now()).millisecondsSinceEpoch;
   }
@@ skipping 357 matching lines @@
     _coPos++;
     _elPos++;
     return _current;
   }
 
   void remove() {
     if (_iterable is List) {
       _coPos--;
       (_iterable as List).remove(_coPos);
     } else if (_iterable is Set) {
-      _iterable.remove(_current);
+      (_iterable as Set).remove(_current);
     } else {
       throw new StateError("Unsupported iterable ${_iterable.runtimeType}");
     }
   }
 }
 
 class MapEntry<K, V> {
   K _key;
   V _value;
   MapEntry(this._key, this._value);
@@ skipping 51 matching lines @@
       }
     } else if (sb.length > newLength) {
       var s = sb.toString().substring(0, newLength);
       sb = new StringBuffer(s);
     }
   }
   void clear() {
     sb = new StringBuffer();
   }
 }