DEP8 failures on xenial

[Andreas Hasenack]

While doing the SRU verification for bug #1834072, two DEP8 failures came up that we believe can be fixed:

a) test/io/console/test_io_console.rb
Apply patch from ruby2.5: https://github.com/ruby/ruby/commit/ac40fc997b6b27c4f61084d9f6fae83ea251d614

b) test/ruby/test_time_tz.rb
Test fails with current tzdata in xenial. It check that these two should be equal, but they are not:
["1911-12-31 23:59:59 -0036", -2192, "-0036", "-00:36", "-00:36:32"],
["1912-01-01 00:36:31 +0000", 0, "+0000", "+00:00", "+00:00:00"],

Downgrading tzdata in xenial to the release version (sudo apt install tzdata=2016d-0ubuntu0.16.04) makes the test pass:
$ ruby2.3 test/runner.rb test/ruby/test_time_tz.rb
Run options:

# Running tests:

Finished tests in 0.056691s, 1940.3463 tests/s, 18186.3371 assertions/s.
110 tests, 1031 assertions, 0 failures, 0 errors, 0 skips

ruby -v: ruby 2.3.1p112 (2016-04-26) [s390x-linux-gnu]

I believe the fix for (b) can be extracted from commit https://github.com/ruby/ruby/commit/4041a4ff759a5a757f032053cba40a4d1e69ee0e (untested)