Fixes #2991. Fix typos and separate tests with external

Language/Types/Type_Void/type_void_A06_t11.dart

@@ -18,3 +18,4 @@ main() {
 //      ^^^^
 // [analyzer] unspecified
 // [cfe] unspecified}
+}

LanguageFeatures/nnbd/static_errors_A04_t21.dart

@@ -8,19 +8,16 @@
 ///
 /// @description Check that it is not an error if a top level or static variable
 /// with a non-nullable type has no initializer expression but is marked with a
-/// `late` or `external `modifier. Test type `Never`.
+/// `late` modifier. Test type `Never`.
 /// @author sgrekhov@unipro.ru
 
 // Requirements=nnbd-strong
 
 late Never n1;
-external Never n2;
 
 class C {
   static late Never n1;
   static late final Never n2;
-  external static  Never n3;
-  external static final Never n4;
 }
 
 main() {

LanguageFeatures/nnbd/static_errors_A04_t22.dart

@@ -8,19 +8,16 @@
 ///
 /// @description Check that it is not an error if a top level or static variable
 /// with a non-nullable type has no initializer expression but is marked with a
-/// `late` or `external `modifier. Test type `Function`.
+/// `late` modifier. Test type `Function`.
 /// @author sgrekhov@unipro.ru
 
 // Requirements=nnbd-strong
 
 late Function x1;
-external Function x2;
 
 class C {
   static late Function x1;
   static late final Function x2;
-  external static Function x3;
-  external static final Function x4;
 }
 
 main() {

LanguageFeatures/nnbd/static_errors_A04_t23.dart

@@ -8,21 +8,18 @@
 ///
 /// @description Check that it is not an error if a top level or static variable
 /// with a non-nullable type has no initializer expression but is marked with a
-/// `late` or `external `modifier. Test a function type.
+/// `late` modifier. Test a function type.
 /// @author sgrekhov@unipro.ru
 
 // Requirements=nnbd-strong
 
 typedef void Foo();
 
 late Foo x1;
-external Foo x2;
 
 class C {
   static late Foo x1;
   static late final Foo x2;
-  external static Foo x3;
-  external static final Foo x4;
 }
 
 main() {

LanguageFeatures/nnbd/static_errors_A04_t24.dart

@@ -8,21 +8,18 @@
 ///
 /// @description Check that it is not an error if a top level or static variable
 /// with a non-nullable type has no initializer expression but is marked with a
-/// `late` or `external `modifier. Test some class.
+/// `late` modifier. Test some class.
 /// @author sgrekhov@unipro.ru
 
 // Requirements=nnbd-strong
 
 class A {}
 
 late A x1;
-external A x2;
 
 class C {
   static late A x1;
   static late final A x2;
-  external static A x3;
-  external static final A x4;
 }
 
 main() {

LanguageFeatures/nnbd/static_errors_A04_t28.dart

@@ -8,21 +8,18 @@
 ///
 /// @description Check that it is not an error if a top level or static variable
 /// with a non-nullable type has no initializer expression but is marked with a
-/// `late` or `external `modifier. Test type `FutureOr<Never>`.
+/// `late` modifier. Test type `FutureOr<Never>`.
 /// @author sgrekhov@unipro.ru
 
 // Requirements=nnbd-strong
 
 import "dart:async";
 
 late FutureOr<Never> x1;
-external FutureOr<Never> x2;
 
 class C {
   static late FutureOr<Never> x1;
   static late final FutureOr<Never> x2;
-  external static FutureOr<Never> x3;
-  external static final FutureOr<Never> x4;
 }
 
 main() {

LanguageFeatures/nnbd/static_errors_A04_t29.dart

@@ -8,8 +8,7 @@
 ///
 /// @description Check that it is not an error if a top level or static variable
 /// with a non-nullable type has no initializer expression but is marked with a
-/// `late` or `external `modifier. Test `FutureOr<F>` where `F` is a function
-/// type.
+/// `late` modifier. Test `FutureOr<F>` where `F` is a function type.
 /// @author sgrekhov@unipro.ru
 
 // Requirements=nnbd-strong
@@ -20,19 +19,12 @@ typedef void Foo();
 
 late FutureOr<Function> f1;
 late FutureOr<Foo> f2;
-external FutureOr<Function> f3;
-external FutureOr<Foo> f4;
 
 class C {
   static late FutureOr<Function> x1;
   static late final FutureOr<Function> x2;
   static late FutureOr<Foo> x3;
   static late final FutureOr<Foo> x4;
-
-  external static FutureOr<Function> x5;
-  external static final FutureOr<Function> x6;
-  external static FutureOr<Foo> x7;
-  external static final FutureOr<Foo> x8;
 }
 
 main() {

LanguageFeatures/nnbd/static_errors_A04_t30.dart

@@ -8,7 +8,7 @@
 ///
 /// @description Check that it is not an error if a top level or static variable
 /// with a non-nullable type has no initializer expression but is marked with a
-/// `late` or `external `modifier. Test `FutureOr<A>` where `A` is some class.
+/// `late` modifier. Test `FutureOr<A>` where `A` is some class.
 /// @author sgrekhov@unipro.ru
 
 // Requirements=nnbd-strong
@@ -18,13 +18,10 @@ import "dart:async";
 class A {}
 
 late FutureOr<A> x1;
-external FutureOr<A> x2;
 
 class C {
   static late FutureOr<A> x1;
   static late final FutureOr<A> x2;
-  external static FutureOr<A> x3;
-  external static final FutureOr<A> x4;
 }
 
 main() {

LanguageFeatures/nnbd/static_errors_A04_t33.dart

@@ -8,8 +8,7 @@
 ///
 /// @description Check that it is not an error if a top level or static variable
 /// with a non-nullable type has no initializer expression but is marked with a
-/// `late` or `external `modifier. Test `FutureOr<FutureOr<A>>` where `A` is
-/// some class.
+/// `late` modifier. Test `FutureOr<FutureOr<A>>` where `A` is some class.
 /// @author sgrekhov@unipro.ru
 
 // Requirements=nnbd-strong
@@ -19,13 +18,10 @@ import "dart:async";
 class A {}
 
 late FutureOr<FutureOr<A>> x1;
-external FutureOr<FutureOr<A>> x2;
 
 class C {
   static late FutureOr<FutureOr<A>> x1;
   static late final FutureOr<FutureOr<A>> x2;
-  external static FutureOr<FutureOr<A>> x3;
-  external static final FutureOr<FutureOr<A>> x4;
 }
 
 main() {

LanguageFeatures/nnbd/static_errors_A04_t35.dart

@@ -0,0 +1,25 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+/// @assertion It is an error if a top level variable or static variable with a
+/// non-nullable type has no initializer expression unless the variable is
+/// marked with a `late` or `external` modifier.
+///
+/// @description Check that it is not an error if a top level or static variable
+/// with a non-nullable type has no initializer expression but is marked with an
+/// `external` modifier. Test type `Never`.
+/// @author sgrekhov22@gmail.com
+
+// Requirements=nnbd-strong
+
+external Never n1;
+
+class C {
+  external static  Never n1;
+  external static final Never n2;
+}
+
+main() {
+  C();
+}

LanguageFeatures/nnbd/static_errors_A04_t36.dart

@@ -0,0 +1,25 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+/// @assertion It is an error if a top level variable or static variable with a
+/// non-nullable type has no initializer expression unless the variable is
+/// marked with a `late` or `external` modifier.
+///
+/// @description Check that it is not an error if a top level or static variable
+/// with a non-nullable type has no initializer expression but is marked with an
+/// `external` modifier. Test type `Function`.
+/// @author sgrekhov22@gmail.com
+
+// Requirements=nnbd-strong
+
+external Function x1;
+
+class C {
+  external static Function x1;
+  external static final Function x2;
+}
+
+main() {
+  new C();
+}

LanguageFeatures/nnbd/static_errors_A04_t37.dart

@@ -0,0 +1,27 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+/// @assertion It is an error if a top level variable or static variable with a
+/// non-nullable type has no initializer expression unless the variable is
+/// marked with a `late` or `external` modifier.
+///
+/// @description Check that it is not an error if a top level or static variable
+/// with a non-nullable type has no initializer expression but is marked with an
+/// `external` modifier. Test a function type.
+/// @author sgrekhov22@gmail.com
+
+// Requirements=nnbd-strong
+
+typedef void Foo();
+
+external Foo x1;
+
+class C {
+  external static Foo x1;
+  external static final Foo x2;
+}
+
+main() {
+  new C();
+}

LanguageFeatures/nnbd/static_errors_A04_t38.dart

@@ -0,0 +1,27 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+/// @assertion It is an error if a top level variable or static variable with a
+/// non-nullable type has no initializer expression unless the variable is
+/// marked with a `late` or `external` modifier.
+///
+/// @description Check that it is not an error if a top level or static variable
+/// with a non-nullable type has no initializer expression but is marked with an
+/// `external` modifier. Test some class.
+/// @author sgrekhov22@gmail.com
+
+// Requirements=nnbd-strong
+
+class A {}
+
+external A x1;
+
+class C {
+  external static A x1;
+  external static final A x2;
+}
+
+main() {
+  new C();
+}

LanguageFeatures/nnbd/static_errors_A04_t39.dart

@@ -0,0 +1,27 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+/// @assertion It is an error if a top level variable or static variable with a
+/// non-nullable type has no initializer expression unless the variable is
+/// marked with a `late` or `external` modifier.
+///
+/// @description Check that it is not an error if a top level or static variable
+/// with a non-nullable type has no initializer expression but is marked with an
+/// `external` modifier. Test type `FutureOr<Never>`.
+/// @author sgrekhov22@gmail.com
+
+// Requirements=nnbd-strong
+
+import "dart:async";
+
+external FutureOr<Never> x1;
+
+class C {
+  external static FutureOr<Never> x1;
+  external static final FutureOr<Never> x2;
+}
+
+main() {
+  new C();
+}

LanguageFeatures/nnbd/static_errors_A04_t40.dart

@@ -0,0 +1,32 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+/// @assertion It is an error if a top level variable or static variable with a
+/// non-nullable type has no initializer expression unless the variable is
+/// marked with a `late` or `external` modifier.
+///
+/// @description Check that it is not an error if a top level or static variable
+/// with a non-nullable type has no initializer expression but is marked with an
+/// `external` modifier. Test `FutureOr<F>` where `F` is a function type.
+/// @author sgrekhov22@gmail.com
+
+// Requirements=nnbd-strong
+
+import "dart:async";
+
+typedef void Foo();
+
+external FutureOr<Function> f1;
+external FutureOr<Foo> f2;
+
+class C {
+  external static FutureOr<Function> x1;
+  external static final FutureOr<Function> x2;
+  external static FutureOr<Foo> x3;
+  external static final FutureOr<Foo> x4;
+}
+
+main() {
+  new C();
+}

LanguageFeatures/nnbd/static_errors_A04_t41.dart

@@ -0,0 +1,29 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+/// @assertion It is an error if a top level variable or static variable with a
+/// non-nullable type has no initializer expression unless the variable is
+/// marked with a `late` or `external` modifier.
+///
+/// @description Check that it is not an error if a top level or static variable
+/// with a non-nullable type has no initializer expression but is marked with an
+/// `external `modifier. Test `FutureOr<A>` where `A` is some class.
+/// @author sgrekhov22@gmail.com
+
+// Requirements=nnbd-strong
+
+import "dart:async";
+
+class A {}
+
+external FutureOr<A> x1;
+
+class C {
+  external static FutureOr<A> x1;
+  external static final FutureOr<A> x2;
+}
+
+main() {
+  new C();
+}