Support the latest version of the analyzer package (#1115)

Author: nex3

pubspec.yaml

@@ -32,7 +32,7 @@ dependencies:
 
 dev_dependencies:
   archive: ">=1.0.0 <3.0.0"
-  analyzer: ">=0.37.0 <0.40.0"
+  analyzer: "^0.40.0"
   cli_pkg: "^1.0.0-beta.10"
   crypto: ">=0.9.2 <3.0.0"
   dart_style: "^1.2.0"

tool/grind/synchronize.dart

@@ -43,7 +43,8 @@ final _sharedClasses = const ['EvaluateResult', 'CompileResult'];
 void synchronize() {
   sources.forEach((source, target) {
     var visitor = _Visitor(File(source).readAsStringSync(), source);
-    parseFile(path: source, featureSet: FeatureSet.fromEnableFlags([]))
+
+    parseFile(path: source, featureSet: FeatureSet.latestLanguageVersion())
         .unit
         .accept(visitor);
     var formatted = DartFormatter().format(visitor.result);