Remove Element.users support.

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

Index: pkg/analyzer/lib/src/generated/utilities_collection.dart
diff --git a/pkg/analyzer/lib/src/generated/utilities_collection.dart b/pkg/analyzer/lib/src/generated/utilities_collection.dart
index 22012ff3e15b0db5395d9a3834b45bfa525c2784..47dd4f61d46e47033baa2fed7cefb8604f64fa94 100644
--- a/pkg/analyzer/lib/src/generated/utilities_collection.dart
+++ b/pkg/analyzer/lib/src/generated/utilities_collection.dart
@@ -469,33 +469,6 @@ class DirectedGraph_SccFinder<N> {
 }
 
 /**
- * An efficient [int] set.
- * Currently not really efficient.
- */
-class IntSet {
-  HashSet<int> _set = new HashSet<int>();
-
-  bool get isEmpty {
-    return _set.isEmpty;
-  }
-
-  void add(int value) {
-    _set.add(value);
-  }
-
-  int remove() {
-    int value = _set.first;
-    _set.remove(value);
-    return value;
-  }
-
-  @override
-  String toString() {
-    return _set.toString();
-  }
-}
-
-/**
  * The class `ListUtilities` defines utility methods useful for working with [List
  ].
  */