Rename rustc_mir to rustc_const_eval.

Author: cjgillot

clippy_utils/src/lib.rs

@@ -17,14 +17,14 @@
 extern crate rustc_ast;
 extern crate rustc_ast_pretty;
 extern crate rustc_attr;
+extern crate rustc_const_eval;
 extern crate rustc_data_structures;
 extern crate rustc_errors;
 extern crate rustc_hir;
 extern crate rustc_infer;
 extern crate rustc_lexer;
 extern crate rustc_lint;
 extern crate rustc_middle;
-extern crate rustc_mir;
 extern crate rustc_session;
 extern crate rustc_span;
 extern crate rustc_target;

clippy_utils/src/qualify_min_const_fn.rs

@@ -366,7 +366,7 @@ fn check_terminator(
 }
 
 fn is_const_fn(tcx: TyCtxt<'_>, def_id: DefId, msrv: Option<&RustcVersion>) -> bool {
-    rustc_mir::const_eval::is_const_fn(tcx, def_id)
+    rustc_const_eval::const_eval::is_const_fn(tcx, def_id)
         && tcx.lookup_const_stability(def_id).map_or(true, |const_stab| {
             if let rustc_attr::StabilityLevel::Stable { since } = const_stab.level {
                 // Checking MSRV is manually necessary because `rustc` has no such concept. This entire