Further cleanups to annotation elements now that #25706 is fixed.

pkg/analyzer/lib/src/dart/constant/utilities.dart

Index: pkg/analyzer/lib/src/dart/constant/utilities.dart
diff --git a/pkg/analyzer/lib/src/dart/constant/utilities.dart b/pkg/analyzer/lib/src/dart/constant/utilities.dart
index 90c8a38482fa175ab1b68af9e1992ee89679fa08..d9ef263205735bf66a475e1d707682475e5572f3 100644
--- a/pkg/analyzer/lib/src/dart/constant/utilities.dart
+++ b/pkg/analyzer/lib/src/dart/constant/utilities.dart
@@ -46,6 +46,13 @@ class ConstantAstCloner extends AstCloner {
   }
 
   @override
+  Annotation visitAnnotation(Annotation node) {
+    Annotation annotation = super.visitAnnotation(node);
+    annotation.element = node.element;
+    return annotation;
+  }
+
+  @override
   FunctionExpression visitFunctionExpression(FunctionExpression node) {
     FunctionExpression expression = super.visitFunctionExpression(node);
     expression.element = node.element;