Read partOf directive metadata lazily.

R=brianwilkerson@google.com

Change-Id: Ida31471bde95b6693a357bcdf6aa94cc96eb587e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/101200
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
diff --git a/pkg/analyzer/lib/src/summary2/ast_binary_reader.dart b/pkg/analyzer/lib/src/summary2/ast_binary_reader.dart
index e7b2b94..4927499 100644
--- a/pkg/analyzer/lib/src/summary2/ast_binary_reader.dart
+++ b/pkg/analyzer/lib/src/summary2/ast_binary_reader.dart
@@ -963,7 +963,7 @@
   PartOfDirective _read_partOfDirective(LinkedNode data) {
     var node = astFactory.partOfDirective(
       _readNode(data.annotatedNode_comment),
-      _readNodeList(data.annotatedNode_metadata),
+      _readNodeListLazy(data.annotatedNode_metadata),
       _getToken(data.directive_keyword),
       _getToken(data.partOfDirective_ofKeyword),
       _readNode(data.partOfDirective_uri),