Remove deprecated api from LibraryBuilder.

pkg/front_end/lib/src/fasta/source/source_loader.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.source_loader;
 
 import 'dart:async' show Future;
 
 import 'dart:typed_data' show Uint8List;
 
@@ skipping 25 matching lines @@
 
 import '../export.dart' show Export;
 
 import '../fasta_codes.dart'
     show
         templateCyclicClassHierarchy,
         templateExtendingEnum,
         templateExtendingRestricted,
         templateIllegalMixin,
         templateIllegalMixinDueToConstructors,
-        templateIllegalMixinDueToConstructorsCause;
+        templateIllegalMixinDueToConstructorsCause,
+        templateUnspecified;
 
 import '../kernel/kernel_shadow_ast.dart' show KernelTypeInferenceEngine;
 
 import '../kernel/kernel_target.dart' show KernelTarget;
 
 import '../loader.dart' show Loader;
 
 import '../parser/class_member_parser.dart' show ClassMemberParser;
 
 import '../scanner.dart' show ErrorToken, ScannerResult, Token, scan;
@@ skipping 54 matching lines @@
     byteCount += bytes.length - 1;
     ScannerResult result = scan(bytes);
     Token token = result.tokens;
     if (!suppressLexicalErrors) {
       List<int> source = getSource(bytes);
       target.addSourceInformation(library.fileUri, result.lineStarts, source);
     }
     while (token is ErrorToken) {
       if (!suppressLexicalErrors) {
         ErrorToken error = token;
-        library.deprecated_addCompileTimeError(
-            token.charOffset, error.assertionMessage,
-            fileUri: uri);
+        library.addCompileTimeError(
+            templateUnspecified.withArguments(error.assertionMessage),
+            token.charOffset,
+            uri);
       }
       token = token.next;
     }
     return token;
   }
 
   List<int> getSource(List<int> bytes) {
     if (excludeSource) return const <int>[];
 
     // bytes is 0-terminated. We don't want that included.
@@ skipping 388 matching lines @@
 
   Expression throwCompileConstantError(Expression error) {
     return target.backendTarget.throwCompileConstantError(coreTypes, error);
   }
 
   Expression deprecated_buildCompileTimeError(String message, int offset) {
     return target.backendTarget
         .buildCompileTimeError(coreTypes, message, offset);
   }
 }