SIMD support for s390x was recently contributed upstream to .NET 10.

Unfortunately, there was no fallback path, and implementations of s390x without support for those specific SIMD instructions (such as z13) would simply fail to run.

Recently the fallback code path was contributed upstream, but missed .NET 10: https://github.com/dotnet/runtime/pull/118376

We need to carry this as a local patch for .NET 10 on RHEL 8 only, otherwise .NET 10 will not work on z13, a supported platform for RHEL 8.