Deprecate all diagnostics methods that use strings.

pkg/kernel/test/closures/suite.dart

Index: pkg/kernel/test/closures/suite.dart
diff --git a/pkg/kernel/test/closures/suite.dart b/pkg/kernel/test/closures/suite.dart
index 6e246fac176b28f27ade41622041c5ab8fd0d1da..d60674f3d37cad3e7cded79d9e773d87f125ddcb 100644
--- a/pkg/kernel/test/closures/suite.dart
+++ b/pkg/kernel/test/closures/suite.dart
@@ -33,7 +33,8 @@ import 'package:front_end/src/fasta/kernel/kernel_target.dart'
 
 import 'package:front_end/src/fasta/translate_uri.dart' show TranslateUri;
 
-import 'package:front_end/src/fasta/errors.dart' show InputError;
+import 'package:front_end/src/fasta/deprecated_problems.dart'
+    show deprecated_InputError;
 
 import 'package:front_end/src/fasta/testing/patched_sdk_location.dart';
 
@@ -116,7 +117,7 @@ class FastaCompile
       await dillTarget.buildOutlines();
       await sourceTarget.buildOutlines();
       p = await sourceTarget.buildProgram();
-    } on InputError catch (e, s) {
+    } on deprecated_InputError catch (e, s) {
       return fail(null, e.error, s);
     }
     return pass(p);