Update to actually use transform

src/librustc_infer/infer/error_reporting/mod.rs

@@ -827,7 +827,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 ty::GenericParamDefKind::Type { has_default, .. } => {
                     Some((param.def_id, has_default))
                 }
-                ty::GenericParamDefKind::Const => None, // FIXME(const_generics:defaults)
+                ty::GenericParamDefKind::Const { .. } => None, // FIXME(const_generics:defaults)
             })
             .peekable();
         let has_default = {

src/librustc_mir/transform/mod.rs

@@ -452,6 +452,7 @@ fn run_optimization_passes<'tcx>(
         &simplify::SimplifyCfg::new("final"),
         &nrvo::RenameReturnPlace,
         &simplify::SimplifyLocals,
+        &match_branches::MatchBranchSimplification,
     ];
 
     let no_optimizations: &[&dyn MirPass<'tcx>] = &[

src/test/mir-opt/matches_reduce_branches.rs

@@ -1,5 +1,4 @@
-// compile-flags: --emit mir
-// EMIT_MIR matches_reduce_branches.foo.fix_match_arms.diff
+// EMIT_MIR matches_reduce_branches.foo.MatchBranchSimplification.diff
 
 fn foo(bar: Option<()>) {
     if matches!(bar, None) {