Enum abstract should be String

[Aurel300]

Another map/abstract-related issue, maybe similar to #9712. This fails compilation on many targets (JS, PHP, Lua), but not others (HL, Eval):

enum abstract Foo(String) {
  var Bar;
}
class Main {
  public static function main():Void {
    new Map<Foo, Int>().exists(Bar);
  }
}

The error is:

Main.hx:6: characters 5-36 : error: Foo should be String
Main.hx:6: characters 5-36 : ... have: (String) -> ...
Main.hx:6: characters 5-36 : ... want: (Foo) -> ...

[RealyUniqueName]

Seems to compile on static targets, but fail on dynamic targets...