Deprecate all diagnostics methods that use strings.

pkg/compiler/tool/generate_kernel.dart

Index: pkg/compiler/tool/generate_kernel.dart
diff --git a/pkg/compiler/tool/generate_kernel.dart b/pkg/compiler/tool/generate_kernel.dart
index c6a24b0a0db44869afb876b88e80a77181e67273..beb01cbda865bab37d65879fccb001b2aabbdabd 100644
--- a/pkg/compiler/tool/generate_kernel.dart
+++ b/pkg/compiler/tool/generate_kernel.dart
@@ -13,7 +13,8 @@ import 'dart:io' show exitCode;
 import 'package:front_end/src/fasta/compiler_command_line.dart'
     show CompilerCommandLine;
 import 'package:front_end/src/fasta/compiler_context.dart' show CompilerContext;
-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/ticker.dart' show Ticker;
 import 'package:compiler/src/kernel/fasta_support.dart' show Dart2jsCompileTask;
 
@@ -28,9 +29,9 @@ main(List<String> arguments) async {
           new Dart2jsCompileTask(c, new Ticker(isVerbose: c.options.verbose));
       await task.compile();
     });
-  } on InputError catch (e) {
+  } on deprecated_InputError catch (e) {
     exitCode = 1;
-    print(e.format());
+    print(e.deprecated_format());
     return null;
   }
 }