message: normalize signature before passing to check_sig_compat
diff: @@ -76,6 +76,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
  let real_sig = instance_ty.fn_sig(self.tcx);
  let sig = self.erase_lifetimes(&sig);
  let real_sig = self.erase_lifetimes(&real_sig);
  + let real_sig = self.tcx.normalize_associated_type(&real_sig);
  if !self.check_sig_compat(sig, real_sig)? {
  return Err(EvalError::FunctionPointerTyMismatch(real_sig, sig));
  }
  