Update imports and rustup

clippy_lints/src/approx_const.rs

@@ -1,6 +1,6 @@
 use crate::utils::span_lint;
 use rustc::hir::*;
-use rustc::lint::*;
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
 use rustc::{declare_lint, lint_array};
 use std::f64::consts as f64;
 use syntax::ast::{FloatTy, Lit, LitKind};