Deprecate all diagnostics methods that use strings.

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

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.messages;
 
 import 'package:kernel/ast.dart' show Library, Location, Program, TreeNode;
 
 import 'util/relativize.dart' show relativizeUri;
 
 import 'compiler_context.dart' show CompilerContext;
 
-import 'errors.dart' show InputError;
+import 'deprecated_problems.dart' show deprecated_InputError;
 
 import 'colors.dart' show cyan, magenta;
 
 const bool hideWarnings = false;
 
 bool get errorsAreFatal => CompilerContext.current.options.errorsAreFatal;
 
 bool get nitsAreFatal => CompilerContext.current.options.nitsAreFatal;
 
 bool get warningsAreFatal => CompilerContext.current.options.warningsAreFatal;
 
 bool get isVerbose => CompilerContext.current.options.verbose;
 
 bool get hideNits => !isVerbose;
 
-void warning(Uri uri, int charOffset, String message) {
+void deprecated_warning(Uri uri, int charOffset, String message) {
   if (hideWarnings) return;
-  print(format(uri, charOffset, colorWarning("Warning: $message")));
+  print(deprecated_format(uri, charOffset, colorWarning("Warning: $message")));
   if (warningsAreFatal) {
     if (isVerbose) print(StackTrace.current);
-    throw new InputError(
+    throw new deprecated_InputError(
         uri, charOffset, "Compilation aborted due to fatal warnings.");
   }
 }
 
-void nit(Uri uri, int charOffset, String message) {
+void deprecated_nit(Uri uri, int charOffset, String message) {
   if (hideNits) return;
-  print(format(uri, charOffset, colorNit("Nit: $message")));
+  print(deprecated_format(uri, charOffset, colorNit("Nit: $message")));
   if (nitsAreFatal) {
     if (isVerbose) print(StackTrace.current);
-    throw new InputError(
+    throw new deprecated_InputError(
         uri, charOffset, "Compilation aborted due to fatal nits.");
   }
 }
 
 String colorWarning(String message) {
   // TODO(ahe): Colors need to be optional. Doesn't work well in Emacs or on
   // Windows.
   return magenta(message);
 }
 
 String colorNit(String message) {
   // TODO(ahe): Colors need to be optional. Doesn't work well in Emacs or on
   // Windows.
   return cyan(message);
 }
 
-String format(Uri uri, int charOffset, String message) {
+String deprecated_format(Uri uri, int charOffset, String message) {
   if (uri != null) {
     String path = relativizeUri(uri);
     Location location = charOffset == -1 ? null : getLocation(path, charOffset);
     String sourceLine = getSourceLine(location);
     if (sourceLine == null) {
       sourceLine = "";
     } else {
       sourceLine = "\n$sourceLine\n"
           "${' ' * (location.column - 1)}^";
     }
@@ skipping 36 matching lines @@
       program.libraries.clear();
       parent.parent = null;
       return result;
     } else {
       return null;
     }
   } else {
     return node.location;
   }
 }