Deprecate all diagnostics methods that use strings.

pkg/front_end/lib/src/fasta/io.dart

Index: pkg/front_end/lib/src/fasta/io.dart
diff --git a/pkg/front_end/lib/src/fasta/io.dart b/pkg/front_end/lib/src/fasta/io.dart
index 4754d94a9838dda04445f2e557036b15e42e0c35..80e5287ee2767ff4dfee4d0c44b750fa66375c28 100644
--- a/pkg/front_end/lib/src/fasta/io.dart
+++ b/pkg/front_end/lib/src/fasta/io.dart
@@ -8,7 +8,7 @@ import 'dart:async' show Future;
 
 import 'dart:io' show FileSystemException;
 
-import 'errors.dart' show inputError;
+import 'deprecated_problems.dart' show deprecated_inputError;
 
 import 'scanner/io.dart' as scanner_io show readBytesFromFile;
 
@@ -23,6 +23,6 @@ Future<List<int>> readBytesFromFile(Uri uri,
     if (osMessage != null && osMessage.isNotEmpty) {
       message = osMessage;
     }
-    return inputError(uri, -1, message);
+    return deprecated_inputError(uri, -1, message);
   }
 }