Rollup merge of #105930 - JakobDegen:nal-unsound, r=oli-obk

Disable `NormalizeArrayLen`

cc #105929

r? mir-opt

compiler/rustc_mir_transform/src/normalize_array_len.rs

@@ -16,7 +16,8 @@ pub struct NormalizeArrayLen;
 
 impl<'tcx> MirPass<'tcx> for NormalizeArrayLen {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
-        sess.mir_opt_level() >= 4
+        // See #105929
+        sess.mir_opt_level() >= 4 && sess.opts.unstable_opts.unsound_mir_opts
     }
 
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {