High Sierra's APFS cannot use invalid filenames [Bug #13816] added workaround for APFS file format. * TestFileExhaustive#test_atime: It fails with nano-sec precise. I changed to use unixtime for this assertion for APFS. * TestFileExhaustive#test_expand_path: skip assertion when given invalid charactor on APFS. [Bug #13816][ruby-core:82383]
merge revision(s) 59602,59887: [Backport #13816]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@62814 b2dd03c8-39d4-4d8f-98ff-823fe69b080e