Use ElementAnnotation as the ConstantEvaluationTarget for annotations.

pkg/analyzer/lib/src/generated/resolver.dart

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index e08f4a1bf39b1089fe2d456ae79fd01ed093a879..fd3d1b06e855a5f72235454b64e96cc373b79864 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -7362,6 +7362,14 @@ class ResolverVisitor extends ScopedVisitor {
     safelyVisit(node.arguments);
     node.accept(elementResolver);
     node.accept(typeAnalyzer);
+    ElementAnnotationImpl elementAnnotationImpl = node.elementAnnotation;
+    if (elementAnnotationImpl == null) {
+      // Analyzer ignores annotations on "part of" directives.
+      assert(parent is PartOfDirective);
+    } else {
+      elementAnnotationImpl.annotationAst =
+          new ConstantAstCloner().cloneNode(node);
+    }
     return null;
   }