Steps to reproduce

ActiveSupport::TimeZone.send(:zones_map).values does not include the Srednekolymsk time zone and instead returns nil for it. Because of that this happens:

ActiveSupport::TimeZone.all
ArgumentError: comparison of NilClass with ActiveSupport::TimeZone failed

Expected behavior

ActiveSupport::TimeZone.all should return a list of TZInfo::DateTimezone objects and not error out.

Actual behavior

An exception is thrown during the sort in the all method due to nil value.

System configuration

Rails version: Rails 5.2.0

Ruby version: ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-linux]