For better consistency change mir_opt_level <= 1 to < 2

compiler/rustc_mir/src/transform/dest_prop.rs

@@ -129,7 +129,7 @@ impl<'tcx> MirPass<'tcx> for DestinationPropagation {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         // Only run at mir-opt-level=2 or higher for now (we don't fix up debuginfo and remove
         // storage statements at the moment).
-        if tcx.sess.mir_opt_level() <= 1 {
+        if tcx.sess.mir_opt_level() < 2 {
             return;
         }
 

compiler/rustc_mir/src/transform/match_branches.rs

@@ -40,7 +40,7 @@
 
 impl<'tcx> MirPass<'tcx> for MatchBranchSimplification {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        if tcx.sess.mir_opt_level() <= 1 {
+        if tcx.sess.mir_opt_level() < 2 {
             return;
         }