Use FastaMessage instead of String. Part 1.

pkg/front_end/lib/src/fasta/kernel/kernel_target.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.kernel_target;
 
 import 'dart:async' show Future;
 
 import 'dart:io' show File;
 
@@ skipping 38 matching lines @@
 import '../source/source_class_builder.dart' show SourceClassBuilder;
 
 import '../target_implementation.dart' show TargetImplementation;
 
 import '../translate_uri.dart' show TranslateUri;
 
 import '../dill/dill_target.dart' show DillTarget;
 
 import '../deprecated_problems.dart'
     show
+        deprecated_formatUnexpected,
         deprecated_InputError,
         deprecated_internalProblem,
         reportCrash,
         resetCrashReporting;
 
+import '../messages.dart' show LocatedMessage;
+
 import '../util/relativize.dart' show relativizeUri;
 
 import '../compiler_context.dart' show CompilerContext;
 
 import 'kernel_builder.dart'
     show
         Builder,
         ClassBuilder,
         InvalidTypeBuilder,
         KernelClassBuilder,
@@ skipping 278 matching lines @@
     ticker.logMs("Wrote deps file");
   }
 
   /// Adds a synthetic field named `#errors` to the main library that contains
   /// [recoverableErrors] formatted.
   ///
   /// If [recoverableErrors] is empty, this method does nothing.
   ///
   /// If there's no main library, this method uses [erroneousProgram] to
   /// replace [program].
-  void handleRecoverableErrors(List<deprecated_InputError> recoverableErrors) {
+  void handleRecoverableErrors(List<LocatedMessage> recoverableErrors) {
     if (recoverableErrors.isEmpty) return;
     KernelLibraryBuilder mainLibrary = loader.first;
     if (mainLibrary == null) {
       program = erroneousProgram(true);
       return;
     }
     List<Expression> expressions = <Expression>[];
-    for (deprecated_InputError error in recoverableErrors) {
-      String message = error.deprecated_format();
+    for (LocatedMessage error in recoverableErrors) {
+      String message = deprecated_formatUnexpected(
+          error.uri, error.charOffset, error.message);
       errors.add(message);
       expressions.add(new StringLiteral(message));
     }
     mainLibrary.library.addMember(new Field(new Name("#errors"),
         initializer: new ListLiteral(expressions, isConst: true),
         isConst: true));
   }
 
   Program erroneousProgram(bool isFullProgram) {
     Uri uri = loader.first?.uri ?? Uri.parse("error:error");
@@ skipping 355 matching lines @@
   }
   for (Constructor constructor in superclass.constructors) {
     if (constructor.name.name.isEmpty) {
       return constructor.function.requiredParameterCount == 0
           ? constructor
           : null;
     }
   }
   return null;
 }