need solution for find error : Error: `TypeInfo` cannot be used with -betterC

[test123]

On Friday, 22 July 2022 at 06:06:09 UTC, test123 wrote:
> some time a huge project build throw error: "Error: `TypeInfo` 
> cannot be used with -betterC"
>
> and it work before some days ago, there is no array allow but 
> throw this error.  no location information (file and line).
>
>
> We need solution to improve the error message so people can 
> find where to fix it.

not my first time find this problem.  but this time is not make 
no sense.


```d
import std.bitmanip : bitfields;

enum UserRole : ubyte {
     None        = 0,
}

alias UserIdT = ushort;

enum BIT_COUNT    = 30;
enum MAX_COUNT    = 2 ^^ BIT_COUNT;

struct UserSession {
     union {
         ulong   uint64;
         mixin(bitfields!(
                 UserIdT,    "user_id",  16,
                 UserRole,    "user_role",   2,
                 uint,       "login_count", BIT_COUNT,
             ));
     }
}

extern(C) void main(){
  	
}

```

there is no array related code, but throw TypeInfo error