Fix more strong mode errors in analyzer

pkg/analyzer/lib/src/context/cache.dart

Index: pkg/analyzer/lib/src/context/cache.dart
diff --git a/pkg/analyzer/lib/src/context/cache.dart b/pkg/analyzer/lib/src/context/cache.dart
index 98e04518c71f5a6c5889d8f2a62a1c8a19105b24..8be0a41b658a3b034501ba2ec492024fec44c3a4 100644
--- a/pkg/analyzer/lib/src/context/cache.dart
+++ b/pkg/analyzer/lib/src/context/cache.dart
@@ -173,12 +173,13 @@ class AnalysisCache {
    * It does not update the cache, if the corresponding [CacheEntry] does not
    * exist, then the default value is returned.
    */
-  Object getValue(AnalysisTarget target, ResultDescriptor result) {
+  Object/*=V*/ getValue/*<V>*/(
+      AnalysisTarget target, ResultDescriptor/*<V>*/ result) {
     CacheEntry entry = get(target);
     if (entry == null) {
       return result.defaultValue;
     }
-    return entry.getValue(result);
+    return entry.getValue(result) as Object/*=V*/;
   }
 
   /**