Compute ElementImpl.hashCode using location.

pkg/analyzer/lib/src/dart/element/element.dart

Index: pkg/analyzer/lib/src/dart/element/element.dart
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index 1ff1de5dbac1ee51b0ab8bf2cb6ea86bb5d050ef..74c0bbaa1730ad5da1a31d8e7645435dd325ab63 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -1801,13 +1801,7 @@ abstract class ElementImpl implements Element {
     // TODO: We might want to re-visit this optimization in the future.
     // We cache the hash code value as this is a very frequently called method.
     if (_cachedHashCode == null) {
-      int hashIdentifier = identifier.hashCode;
-      Element enclosing = enclosingElement;
-      if (enclosing != null) {
-        _cachedHashCode = hashIdentifier + enclosing.hashCode;
-      } else {
-        _cachedHashCode = hashIdentifier;
-      }
+      _cachedHashCode = location.hashCode;
     }
     return _cachedHashCode;
   }