Refactor regression_44985_test.dart

Change-Id: I0e5788dd5e0636927df1e961cc00b104bc2b21a9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/409843
Commit-Queue: Daco Harkes <[email protected]>
Reviewed-by: Daco Harkes <[email protected]>

Author: goderbauer

runtime/docs/contributing_to_dart_ffi.md

@@ -89,7 +89,7 @@ Unit tests
 
 Integration tests
 
-- `tests/ffi/static_checks/(.*)_test.dart`. Prefer creating new tests with the “new style” `// [analyzer] ...`. The tests can be run with `$ tools/build.py -mrelease runtime create_platform_sdk && tools/test.py -cfasta -mrelease tests/ffi/static_checks/vmspecific_static_checks_array_test.dart`. These tests require rebuilding the SDK. These tests also can contain `// [cfe] ...` error expectations. Which makes them good for checking that the behavior is similar in the CFE and analyzer implementation. And because these test files are standalone Dart, you can easily pass them as an argument to the analyzer when running from source in the debugger.
+- `tests/ffi/static_checks/(.*)_test.dart`. Prefer creating new tests with the “new style” `// [analyzer] ...`. The tests can be run with `$ tools/build.py -mrelease runtime create_platform_sdk && tools/test.py -cfasta -cdart2analyzer -mrelease tests/ffi/static_checks/vmspecific_static_checks_array_test.dart`. These tests require rebuilding the SDK. These tests also can contain `// [cfe] ...` error expectations. Which makes them good for checking that the behavior is similar in the CFE and analyzer implementation. And because these test files are standalone Dart, you can easily pass them as an argument to the analyzer when running from source in the debugger.
 
 
 ## Running in the debugger

tests/ffi/static_checks/regress_44985_test.dart

@@ -2,15 +2,16 @@
 // 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.
 
-// Formatting can break multitests, so don't format them.
-// dart format off
-
 import "dart:ffi";
 
 final class S2 extends Struct {
   external Pointer<Int8> notEmpty;
 
-  external Struct? s; //# 01: compile-time error
+  external Struct? s;
+  //       ^^^^^^^
+  // [analyzer] COMPILE_TIME_ERROR.INVALID_FIELD_TYPE_IN_STRUCT
+  //               ^
+  // [cfe] Field 's' cannot be nullable or have type 'Null', it must be `int`, `double`, `Pointer`, or a subtype of `Struct` or `Union`.
 }
 
 void main() {