test_time_tz.rb: past Japanese DST tzdata fix
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62506 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_time_tz.rb: past Japanese DST tzdata fix
the tzdata 2018 fix of Japanese DST transitions (1948-1951).
[ruby-core:85373] [Bug #14438]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62506 b2dd03c8-39d4-4d8f-98ff-823fe69b080e