Set CacheEntry.target in the contructor.

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

Index: pkg/analyzer/lib/src/context/context.dart
diff --git a/pkg/analyzer/lib/src/context/context.dart b/pkg/analyzer/lib/src/context/context.dart
index 599bb4cc8c9477ffb1bd4750beb70d6d64e0d3df..5cf5af512bdaa5dc431e71326285463fa54b87ea 100644
--- a/pkg/analyzer/lib/src/context/context.dart
+++ b/pkg/analyzer/lib/src/context/context.dart
@@ -701,8 +701,8 @@ class AnalysisContextImpl implements InternalAnalysisContext {
   cache.CacheEntry getCacheEntry(AnalysisTarget target) {
     cache.CacheEntry entry = _cache.get(target);
     if (entry == null) {
-      entry = new cache.CacheEntry();
-      _cache.put(target, entry);
+      entry = new cache.CacheEntry(target);
+      _cache.put(entry);
     }
     return entry;
   }
@@ -1430,10 +1430,10 @@ class AnalysisContextImpl implements InternalAnalysisContext {
    * entry that was created.
    */
   cache.CacheEntry _createCacheEntry(Source source, bool explicitlyAdded) {
-    cache.CacheEntry entry = new cache.CacheEntry();
+    cache.CacheEntry entry = new cache.CacheEntry(source);
     entry.modificationTime = getModificationStamp(source);
     entry.explicitlyAdded = explicitlyAdded;
-    _cache.put(source, entry);
+    _cache.put(entry);
     return entry;
   }