Errors when using $this in trait

[roberthusak]

Test case:

<?php
trait T {
  public function bar() {
    return $this instanceof C;
  }
}
class C {
  use T;
}
echo (new C)->bar();

Expected result: 1
Actual result: NotImplementedException thrown from CodeGenerator.EmitAsObject(TypeSymbol, bool) during compilation.

The same happens in the case of CodeGenerator.EmitConvertToPhpValue.