strip_expr_helper
return strip_expr_helper(expr->cast_expression, set_parent);
unop = strip_expr_helper(expr->unop, set_parent);
return strip_expr_helper(unop->unop, set_parent);
return strip_expr_helper(expr->cond_true, set_parent);
return strip_expr_helper(expr->conditional, set_parent);
return strip_expr_helper(expr->cond_false, set_parent);
return strip_expr_helper(expr, set_parent);
return strip_expr_helper(expr, false);
return strip_expr_helper(expr, true);