Bump version to 3.4.

Do not revert: The main channel version must be upgraded now that the
version 3.3 beta has been cut and reverting this change puts the
release infrastructure into an unsupported state. Please fix forward
any potential problems that occur downstream and loop me into the
discussions so we can improve the release procedures in the future.

Change-Id: I8706c3d74fe0474d34a99c5cbbb8e9a88b586cdd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/329902
Commit-Queue: Jonas Termansen <sortie@google.com>
Reviewed-by: Kevin Chisholm <kevinjchisholm@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>

CHANGELOG.md

@@ -1,3 +1,5 @@
+## 3.4.0
+
 ## 3.3.0
 
 ### Language

pkg/_fe_analyzer_shared/lib/src/experiments/flags.dart

@@ -6,7 +6,7 @@
 //
 // Instead modify 'tools/experimental_features.yaml' and run
 // 'dart pkg/front_end/tool/fasta.dart generate-experimental-flags' to update.
-const Version defaultLanguageVersion = const Version(3, 3);
+const Version defaultLanguageVersion = const Version(3, 4);
 
 /// Enum for experimental flags shared between the CFE and the analyzer.
 enum ExperimentalFlag {

pkg/analyzer/lib/src/dart/analysis/experiments.g.dart

@@ -12,7 +12,7 @@ part of 'experiments.dart';
 
 /// The current version of the Dart language (or, for non-stable releases, the
 /// version of the language currently in the process of being developed).
-const _currentVersion = '3.3.0';
+const _currentVersion = '3.4.0';
 
 /// A map containing information about all known experimental flags.
 final _knownFeatures = <String, ExperimentalFeature>{

pkg/kernel/lib/default_language_version.dart

@@ -9,4 +9,4 @@
 
 import "ast.dart";
 
-const Version defaultLanguageVersion = const Version(3, 3);
+const Version defaultLanguageVersion = const Version(3, 4);

pkg/vm_service/test/step_through_extension_type_method_call_test.dart

@@ -3,7 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 // VMOptions=--enable-experiment=inline-class
-// @dart=3.3
+// @dart=3.4
 // ignore_for_file: experiment_not_enabled,undefined_class,undefined_function
 
 import 'package:test/test.dart';

tools/VERSION

@@ -25,7 +25,7 @@
 #
 CHANNEL main
 MAJOR 3
-MINOR 3
+MINOR 4
 PATCH 0
 PRERELEASE 0
 PRERELEASE_PATCH 0

tools/experimental_features.yaml

@@ -109,7 +109,7 @@
 # default 'language' "category" with code generated for both CFE and Analyzer,
 # while other categories can be tailored more specifically.
 
-current-version: '3.3.0'
+current-version: '3.4.0'
 
 features:
   variance: