pkg/front_end/testcases/invalid_assignment.dart:12:5: Context: Write to i@300
  i = 1;
    ^
pkg/front_end/testcases/invalid_assignment.dart:13:5: Context: Write to i@300
  i = /*@error=InvalidAssignment*/ s;
    ^
pkg/front_end/testcases/invalid_assignment.dart:14:5: Context: Write to i@300
  i ??= 1;
    ^^^
pkg/front_end/testcases/invalid_assignment.dart:15:5: Context: Write to i@300
  i ??= /*@error=InvalidAssignment*/ s;
    ^^^
pkg/front_end/testcases/invalid_assignment.dart:16:5: Context: Write to a@315
  a = new A();
    ^
pkg/front_end/testcases/invalid_assignment.dart:17:34: Context: Write to a@315
  a /*@error=InvalidAssignment*/ += 1;
                                 ^^