Implement some missed methods for summary2 support

Change-Id: I18cbec26512c4d660b6dbc3ea1e5325ff032a8d2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/113753
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
diff --git a/pkg/analyzer/lib/src/summary2/ast_text_printer.dart b/pkg/analyzer/lib/src/summary2/ast_text_printer.dart
index 586123a..426c86f 100644
--- a/pkg/analyzer/lib/src/summary2/ast_text_printer.dart
+++ b/pkg/analyzer/lib/src/summary2/ast_text_printer.dart
@@ -333,6 +333,26 @@
   }
 
   @override
+  void visitExtensionDeclaration(ExtensionDeclaration node) {
+    _compilationUnitMember(node);
+    _token(node.extensionKeyword);
+    node.name?.accept(this);
+    node.typeParameters?.accept(this);
+    _token(node.onKeyword);
+    node.extendedType.accept(this);
+    _token(node.leftBracket);
+    node.members.accept(this);
+    _token(node.rightBracket);
+  }
+
+  @override
+  void visitExtensionOverride(ExtensionOverride node) {
+    node.extensionName.accept(this);
+    node.typeArguments.accept(this);
+    node.argumentList.accept(this);
+  }
+
+  @override
   void visitFieldDeclaration(FieldDeclaration node) {
     _classMember(node);
     _token(node.staticKeyword);