#![deny(rustc::diagnostic_outside_of_impl)]
use rustc_data_structures::graph::scc::Sccs;
-use rustc_index::vec::{IndexSlice, IndexVec};
+use rustc_index::{IndexSlice, IndexVec};
use rustc_middle::mir::ConstraintCategory;
use rustc_middle::ty::{RegionVid, VarianceDiagInfo};
use rustc_span::Span;