return unfixed len if pat has reported error
- Fixes#116186
- Fixes#113021
This issue arises due to the creation of a fixed-length pattern, as a result of the mir body corruption. The corruption taints `tcx.eval_to_allocation_raw`, causing it to return `AlreadyReported`. Consequently, this prevents `len.try_eval_target_usize` from evaluating correctly and returns `None`. Lastly, it results in the return of `[usize; min_len]`.
To rectify this issue, my approach is that to return unfixed when encountering `ErrorHandled::Reported`. Additionally, in instances of `ErrorHandled::TooGeneric`, the previous logic has been reinstated.