Migration: add a repro for an issue with field formal parameters.

See #38453.

Change-Id: I7ecf1c020437b7e332e7646cc40e947f38a081bf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/117687
Reviewed-by: Samuel Rawlins <[email protected]>
Commit-Queue: Paul Berry <[email protected]>

Author: stereotype441

pkg/nnbd_migration/test/api_test.dart

@@ -3040,6 +3040,27 @@ void h(bool b, int? i) {
 main() {
   h(false, null);
 }
+''';
+    await _checkSingleFileChanges(content, expected);
+  }
+
+  @FailingTest(issue: 'https://github.com/dart-lang/sdk/issues/38453')
+  test_unconditional_use_of_field_formal_param_does_not_create_hard_edge() async {
+    var content = '''
+class C {
+  int i;
+  int j;
+  C.one(this.i) : j = i + 1;
+  C.two() : i = null, j = 0;
+}
+''';
+    var expected = '''
+class C {
+  int? i;
+  int j;
+  C.one(this.i) : j = i! + 1;
+  C.two() : i = null, j = 0;
+}
 ''';
     await _checkSingleFileChanges(content, expected);
   }