use rustc::hir::map::Map;
use rustc::session::config::nightly_options;
+use rustc::session::parse::feature_err;
use rustc::ty::query::Providers;
use rustc::ty::TyCtxt;
-use rustc_error_codes::*;
use rustc_errors::struct_span_err;
use rustc_hir as hir;
use rustc_hir::def_id::DefId;
use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
use rustc_span::{sym, Span, Symbol};
use syntax::ast::Mutability;
-use syntax::feature_gate::feature_err;
use std::fmt;