support class native clause

pkg/analyzer/lib/src/dart/error/syntactic_errors.dart

Index: pkg/analyzer/lib/src/dart/error/syntactic_errors.dart
diff --git a/pkg/analyzer/lib/src/dart/error/syntactic_errors.dart b/pkg/analyzer/lib/src/dart/error/syntactic_errors.dart
index 1424c62a2ecffc837ae04d1b6cda368002629bce..5e5e176da4cf01afa6cb29eedb9b76e82c35ec73 100644
--- a/pkg/analyzer/lib/src/dart/error/syntactic_errors.dart
+++ b/pkg/analyzer/lib/src/dart/error/syntactic_errors.dart
@@ -744,6 +744,13 @@ class ParserErrorCode extends ErrorCode {
           "loaded through native extensions.",
           "Try removing the word 'native'.");
 
+  static const ParserErrorCode NATIVE_CLAUSE_SHOULD_BE_ANNOTATION =
+      const ParserErrorCode(
+          'NATIVE_CLAUSE_SHOULD_BE_ANNOTATION',
+          "Native clause in this form is deprecated.",
+          "Try removing this native clause and adding @native()"
+          " or @native('some-text-here') before the declaration.");

[ahe, 2017/08/21 12:04:10]

'some-text-here' -> 'native-name'

[danrubel, 2017/08/22 01:35:27]

Good suggestion. Fixed here and in messages.yaml.

+
   static const ParserErrorCode NON_CONSTRUCTOR_FACTORY = const ParserErrorCode(
       'NON_CONSTRUCTOR_FACTORY',
       "Only a constructor can be declared to be a factory.",