Dot shorthands: Add experiment release version.

Added an experiment released version for Dart 3.9.

Context:
https://github.com/dart-lang/webdev/blob/main/fixtures/_experimentSound/web/main.dart
and tests outside of the SDK broke once we bumped to 3.10.
The experiment released version will allow us to use dot shorthands in
the 3.9 version.

Bug: #57037
Change-Id: I066d366f36e3ce1debb7b3e0e492b6a61bcddb74
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/442162
Reviewed-by: Paul Berry <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Kallen Tu <[email protected]>
Reviewed-by: Nate Bosch <[email protected]>

Author: kallentu

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

@@ -64,7 +64,7 @@ enum ExperimentalFlag {
       isEnabledByDefault: false,
       isExpired: false,
       experimentEnabledVersion: defaultLanguageVersion,
-      experimentReleasedVersion: defaultLanguageVersion),
+      experimentReleasedVersion: const Version(3, 9)),
 
   enhancedEnums(
       name: 'enhanced-enums',

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

@@ -268,7 +268,7 @@ class ExperimentalFeatures {
     isEnabledByDefault: IsEnabledByDefault.dot_shorthands,
     isExpired: IsExpired.dot_shorthands,
     documentation: 'Shorter dot syntax for static accesses.',
-    experimentalReleaseVersion: null,
+    experimentalReleaseVersion: Version.parse('3.9.0'),
     releaseVersion: null,
     channels: ["stable", "beta", "dev", "main"],
   );

pkg/front_end/lib/src/api_prototype/experimental_flags_generated.dart

@@ -121,7 +121,7 @@ class ExperimentalFlag {
       isExpired: false,
       enabledVersion: defaultLanguageVersion,
       experimentEnabledVersion: defaultLanguageVersion,
-      experimentReleasedVersion: defaultLanguageVersion);
+      experimentReleasedVersion: const Version(3, 9));
 
   static const ExperimentalFlag enhancedEnums = const ExperimentalFlag(
       name: 'enhanced-enums',

tools/experimental_features.yaml

@@ -147,6 +147,7 @@ features:
     help: "A bundle of updates to type inference."
 
   dot-shorthands:
+    experimentalReleaseVersion: '3.9.0'
     help: "Shorter dot syntax for static accesses."
 
 # Experiment flag only used for testing.