File.utime() not working on s390x

[jcharaoui]

Hello, since I started working on the Debian package of JRuby, I noticed that File.utime() calls would (silently) fail to modify a file's mtime. This happens not only with the Debian-packaged JRuby, but also with a vanilla build from HEAD. This leads to many parts of the test suite failing, eg.:

TestFile#test_utime = 0.02 s                               
  1) Failure:
TestFile#test_utime [/home/lavamind/jruby/test/mri/ruby/test_file.rb:357]:
[ruby-core:44776].
<2011-05-27 20:10:39 +0000> expected but was
<2023-12-17 15:52:21.156216792 +0000>.

but there are many other examples related to File.utime not working.

I'm not seeing such failures on other architectures.

Using CRuby however, File.utime() works and the test case above passes without issue.