array.c add back shared array optimization to ary_ensure_room_for_unshift
Bug fix in commit ec8e5f5aa64e2a [Bug #15952] disabled an optimization in this function.
Closes: https://github.com/ruby/ruby/pull/2252
array.c add back shared array optimization to ary_ensure_room_for_unshift
Bug fix in commit ec8e5f5aa64e2a [Bug #15952] disabled an
optimization in this function.
Closes: https://github.com/ruby/ruby/pull/2252