Add line starts into unlinked units.

pkg/analyzer/test/src/summary/resynthesize_ast_test.dart

Index: pkg/analyzer/test/src/summary/resynthesize_ast_test.dart
diff --git a/pkg/analyzer/test/src/summary/resynthesize_ast_test.dart b/pkg/analyzer/test/src/summary/resynthesize_ast_test.dart
index cb6cfeb2ec1f3383c446e0e09543cfc5583efae2..62a5bea0131c9b24dc1a064499c9471d2b09ec37 100644
--- a/pkg/analyzer/test/src/summary/resynthesize_ast_test.dart
+++ b/pkg/analyzer/test/src/summary/resynthesize_ast_test.dart
@@ -20,6 +20,7 @@ import 'package:analyzer/src/summary/summarize_ast.dart';
 import 'package:analyzer/src/summary/summarize_elements.dart'
     show PackageBundleAssembler;
 import 'package:analyzer/task/dart.dart' show PARSED_UNIT;
+import 'package:analyzer/task/general.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../reflective_tests.dart';
@@ -791,7 +792,9 @@ abstract class _AstResynthesizeTestMixin {
     }
     return uriToUnit.putIfAbsent(uriStr, () {
       CompilationUnit unit = context.computeResult(source, PARSED_UNIT);
-      UnlinkedUnitBuilder unlinkedUnit = serializeAstUnlinked(unit);
+      LineInfo lineInfo = context.computeResult(source, LINE_INFO);
+      UnlinkedUnitBuilder unlinkedUnit =
+          serializeAstUnlinked(unit, lineInfo.lineStarts);
       bundleAssembler.addUnlinkedUnit(source, unlinkedUnit);
       return unlinkedUnit;
     });