[js_ast] language version 2.16

Change-Id: I421fe264e7318bf774d25cce463e858e9323872a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/240145
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Commit-Queue: Stephen Adams <sra@google.com>
diff --git a/.dart_tool/package_config.json b/.dart_tool/package_config.json
index d7bbb38..0b5e2e4 100644
--- a/.dart_tool/package_config.json
+++ b/.dart_tool/package_config.json
@@ -386,7 +386,7 @@
       "name": "js_ast",
       "rootUri": "../pkg/js_ast",
       "packageUri": "lib/",
-      "languageVersion": "2.10"
+      "languageVersion": "2.16"
     },
     {
       "name": "js_runtime",
diff --git a/pkg/js_ast/lib/js_ast.dart b/pkg/js_ast/lib/js_ast.dart
index 024d331..68475ef 100644
--- a/pkg/js_ast/lib/js_ast.dart
+++ b/pkg/js_ast/lib/js_ast.dart
@@ -2,8 +2,6 @@
 // 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.
 
-// @dart = 2.10
-
 library js_ast;
 
 export 'src/builder.dart';
diff --git a/pkg/js_ast/lib/src/builder.dart b/pkg/js_ast/lib/src/builder.dart
index 60b5171..fc04678 100644
--- a/pkg/js_ast/lib/src/builder.dart
+++ b/pkg/js_ast/lib/src/builder.dart
@@ -2,8 +2,6 @@
 // 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.
 
-// @dart=2.15
-
 /// Utilities for building JS ASTs at runtime. Contains a builder class and a
 /// parser that parses part of the language.
 library js_ast.builder;
diff --git a/pkg/js_ast/lib/src/equivalence_visitor.dart b/pkg/js_ast/lib/src/equivalence_visitor.dart
index 5f67e72..598926b 100644
--- a/pkg/js_ast/lib/src/equivalence_visitor.dart
+++ b/pkg/js_ast/lib/src/equivalence_visitor.dart
@@ -2,8 +2,6 @@
 // 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.
 
-// @dart=2.15
-
 library js_ast.equivalence_visitor;
 
 import 'nodes.dart';
diff --git a/pkg/js_ast/lib/src/nodes.dart b/pkg/js_ast/lib/src/nodes.dart
index b36a52a..fab2e1b 100644
--- a/pkg/js_ast/lib/src/nodes.dart
+++ b/pkg/js_ast/lib/src/nodes.dart
@@ -2,8 +2,6 @@
 // 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.
 
-// @dart=2.15
-
 library js_ast.nodes;
 
 import 'precedence.dart';
diff --git a/pkg/js_ast/lib/src/precedence.dart b/pkg/js_ast/lib/src/precedence.dart
index 19c5c9f..222f4a8 100644
--- a/pkg/js_ast/lib/src/precedence.dart
+++ b/pkg/js_ast/lib/src/precedence.dart
@@ -2,8 +2,6 @@
 // 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.
 
-// @dart=2.15
-
 library precedence;
 
 const EXPRESSION = 0;
diff --git a/pkg/js_ast/lib/src/printer.dart b/pkg/js_ast/lib/src/printer.dart
index 4e1e59c..9f9a3ff 100644
--- a/pkg/js_ast/lib/src/printer.dart
+++ b/pkg/js_ast/lib/src/printer.dart
@@ -2,8 +2,6 @@
 // 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.
 
-// @dart=2.15
-
 library js_ast.printer;
 
 import 'characters.dart' as char_codes;
diff --git a/pkg/js_ast/lib/src/strings.dart b/pkg/js_ast/lib/src/strings.dart
index ddbe407..9ca5836 100644
--- a/pkg/js_ast/lib/src/strings.dart
+++ b/pkg/js_ast/lib/src/strings.dart
@@ -2,8 +2,6 @@
 // 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.
 
-// @dart=2.15
-
 // Utilities for converting between JavaScript source-code Strings and the
 // String value they represent.
 
diff --git a/pkg/js_ast/lib/src/template.dart b/pkg/js_ast/lib/src/template.dart
index 9e049fd..2fb0254 100644
--- a/pkg/js_ast/lib/src/template.dart
+++ b/pkg/js_ast/lib/src/template.dart
@@ -2,8 +2,6 @@
 // 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.
 
-// @dart=2.15
-
 library js_ast.template;
 
 import 'nodes.dart';
diff --git a/pkg/js_ast/pubspec.yaml b/pkg/js_ast/pubspec.yaml
index 27f1857..4afc01e 100644
--- a/pkg/js_ast/pubspec.yaml
+++ b/pkg/js_ast/pubspec.yaml
@@ -3,7 +3,7 @@
 publish_to: none
 
 environment:
-  sdk: '>=2.10.0 <3.0.0'
+  sdk: '>=2.16.0 <3.0.0'
 
 dev_dependencies:
   expect: