Removed fixed dependencies

packages/analyzer/lib/dart/ast/syntactic_entity.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library analyzer.dart.ast.syntactic_entity;
+
+/**
+ * Interface representing a syntactic entity (either a token or an AST node)
+ * which has a location and extent in the source file.
+ */
+abstract class SyntacticEntity {
+  /**
+   * Return the offset from the beginning of the file to the character after the
+   * last character of the syntactic entity.
+   */
+  int get end;
+
+  /**
+   * Return the number of characters in the syntactic entity's source range.
+   */
+  int get length;
+
+  /**
+   * Return the offset from the beginning of the file to the first character in
+   * the syntactic entity.
+   */
+  int get offset;
+}