Fixing analyzer warnings on overloading == but not get hashCode.

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index cbcbe5a87517db15e6b96df39415e39e36a1ae92..102d4da2c215a29cbe2fb92f330f1c3acbb19079 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -24508,6 +24508,9 @@ class _ClientRect implements Rect native "ClientRect" {
         height == other.height;
   }
 
+  int get hashCode => JenkinsSmiHash.hash4(left.hashCode, top.hashCode,
+      width.hashCode, height.hashCode);
+
   /**
    * Computes the intersection of this rectangle and the rectangle parameter.
    * Returns null if there is no intersection.
@@ -27611,6 +27614,8 @@ class Point {
     return x == other.x && y == other.y;
   }
 
+  int get hashCode => JenkinsSmiHash.hash2(x.hashCode, y.hashCode);
+
   Point operator +(Point other) {
     return new Point(x + other.x, y + other.y);
   }
@@ -27733,6 +27738,9 @@ class Rect {
         height == other.height;
   }
 
+  int get hashCode => JenkinsSmiHash.hash4(left.hashCode, top.hashCode,
+      width.hashCode, height.hashCode);
+
   /**
    * Computes the intersection of this rectangle and the rectangle parameter.
    * Returns null if there is no intersection.