[cfe] Add test for issue 53751

Closes #53751

Change-Id: I4b0a081ff904b2e2b097d47aaa09a04c8795e105
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/335045
Reviewed-by: Jens Johansen <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

pkg/front_end/testcases/extension_types/issue53751.dart

@@ -0,0 +1,6 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by b
+// BSD-style license that can be found in the LICENSE file.
+
+extension type const E(int? n) {}
+const E e = null as E;

pkg/front_end/testcases/extension_types/issue53751.dart.strong.expect

@@ -0,0 +1,20 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+extension type E(core::int? n) {
+  abstract extension-type-member representation-field get n() → core::int?;
+  constructor • = self::E|constructor#;
+  constructor tearoff • = self::E|constructor#_#new#tearOff;
+}
+static const field self::E /* = core::int? */ e = #C1;
+static extension-type-member method E|constructor#(core::int? n) → self::E /* = core::int? */ {
+  lowered final self::E /* = core::int? */ #this = n;
+  return #this;
+}
+static extension-type-member method E|constructor#_#new#tearOff(core::int? n) → self::E /* = core::int? */
+  return self::E|constructor#(n);
+
+constants  {
+  #C1 = null
+}

pkg/front_end/testcases/extension_types/issue53751.dart.strong.transformed.expect

@@ -0,0 +1,20 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+extension type E(core::int? n) {
+  abstract extension-type-member representation-field get n() → core::int?;
+  constructor • = self::E|constructor#;
+  constructor tearoff • = self::E|constructor#_#new#tearOff;
+}
+static const field self::E /* = core::int? */ e = #C1;
+static extension-type-member method E|constructor#(core::int? n) → self::E /* = core::int? */ {
+  lowered final self::E /* = core::int? */ #this = n;
+  return #this;
+}
+static extension-type-member method E|constructor#_#new#tearOff(core::int? n) → self::E /* = core::int? */
+  return self::E|constructor#(n);
+
+constants  {
+  #C1 = null
+}

pkg/front_end/testcases/extension_types/issue53751.dart.textual_outline.expect

@@ -0,0 +1,2 @@
+extension type const E(int? n) {}
+const E e = null as E;

pkg/front_end/testcases/extension_types/issue53751.dart.textual_outline_modelled.expect

@@ -0,0 +1,2 @@
+const E e = null as E;
+extension type const E(int? n) {}

pkg/front_end/testcases/extension_types/issue53751.dart.weak.expect

@@ -0,0 +1,20 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+extension type E(core::int? n) {
+  abstract extension-type-member representation-field get n() → core::int?;
+  constructor • = self::E|constructor#;
+  constructor tearoff • = self::E|constructor#_#new#tearOff;
+}
+static const field self::E /* = core::int? */ e = #C1;
+static extension-type-member method E|constructor#(core::int? n) → self::E /* = core::int? */ {
+  lowered final self::E /* = core::int? */ #this = n;
+  return #this;
+}
+static extension-type-member method E|constructor#_#new#tearOff(core::int? n) → self::E /* = core::int? */
+  return self::E|constructor#(n);
+
+constants  {
+  #C1 = null
+}

pkg/front_end/testcases/extension_types/issue53751.dart.weak.modular.expect

@@ -0,0 +1,20 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+extension type E(core::int? n) {
+  abstract extension-type-member representation-field get n() → core::int?;
+  constructor • = self::E|constructor#;
+  constructor tearoff • = self::E|constructor#_#new#tearOff;
+}
+static const field self::E /* = core::int? */ e = #C1;
+static extension-type-member method E|constructor#(core::int? n) → self::E /* = core::int? */ {
+  lowered final self::E /* = core::int? */ #this = n;
+  return #this;
+}
+static extension-type-member method E|constructor#_#new#tearOff(core::int? n) → self::E /* = core::int? */
+  return self::E|constructor#(n);
+
+constants  {
+  #C1 = null
+}

pkg/front_end/testcases/extension_types/issue53751.dart.weak.outline.expect

@@ -0,0 +1,19 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+extension type E(core::int? n) {
+  abstract extension-type-member representation-field get n() → core::int?;
+  constructor • = self::E|constructor#;
+  constructor tearoff • = self::E|constructor#_#new#tearOff;
+}
+static const field self::E /* = core::int? */ e = null as self::E /* = core::int? */;
+static extension-type-member method E|constructor#(core::int? n) → self::E /* = core::int? */
+  ;
+static extension-type-member method E|constructor#_#new#tearOff(core::int? n) → self::E /* = core::int? */
+  return self::E|constructor#(n);
+
+
+Extra constant evaluation status:
+Evaluated: AsExpression @ org-dartlang-testcase:///issue53751.dart:6:18 -> NullConstant(null)
+Extra constant evaluation: evaluated: 3, effectively constant: 1

pkg/front_end/testcases/extension_types/issue53751.dart.weak.transformed.expect

@@ -0,0 +1,20 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+extension type E(core::int? n) {
+  abstract extension-type-member representation-field get n() → core::int?;
+  constructor • = self::E|constructor#;
+  constructor tearoff • = self::E|constructor#_#new#tearOff;
+}
+static const field self::E /* = core::int? */ e = #C1;
+static extension-type-member method E|constructor#(core::int? n) → self::E /* = core::int? */ {
+  lowered final self::E /* = core::int? */ #this = n;
+  return #this;
+}
+static extension-type-member method E|constructor#_#new#tearOff(core::int? n) → self::E /* = core::int? */
+  return self::E|constructor#(n);
+
+constants  {
+  #C1 = null
+}