Generate artificial hashCode for often used classes.

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

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 209e9fdcbe94b9439c7efc6883e6844201609d10..fc2696d417ca76784b8da0d939173ab7cc71446f 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -10078,6 +10078,16 @@ class ResolvableLibrary {
   static List<ResolvableLibrary> _EMPTY_ARRAY = new List<ResolvableLibrary>(0);
 
   /**
+   * The next artificial hash code.
+   */
+  static int _NEXT_HASH_CODE = 0;
+
+  /**
+   * The artifitial hash code for this object.
+   */
+  final int _hashCode = _NEXT_HASH_CODE++;
+
+  /**
    * The source specifying the defining compilation unit of this library.
    */
   final Source librarySource;
@@ -10197,6 +10207,9 @@ class ResolvableLibrary {
    */
   List<ResolvableLibrary> get exports => _exportedLibraries;
 
+  @override
+  int get hashCode => _hashCode;
+
   /**
    * Set the libraries that are imported into this library to be those in the given array.
    *