merge revision(s) fa85d23ff4a02985ebfe0716b0ff768f5b4fe13d: [Backport #21380]
[Bug #21380] Prohibit modification in String#split block Reported at https://hackerone.com/reports/3163876
merge revision(s) fa85d23ff4a02985ebfe0716b0ff768f5b4fe13d: [Backport #21380]