* test/ruby/test_io.rb (ruby): check the existence of the constant instead of

checking platform.  see also r52277.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52357 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_io.rb

@@ -1081,7 +1081,7 @@ class TestIO < Test::Unit::TestCase
     args = ['-e', '$>.write($<.read)'] if args.empty?
     ruby = EnvUtil.rubybin
     opts = {}
-    opts[:rlimit_nproc] = 1024 if /mswin|mingw/ =~ RUBY_PLATFORM
+    opts[:rlimit_nproc] = 1024 if defined?(Process::RLIMIT_NPROC)
     f = IO.popen([ruby] + args, 'r+', opts)
     pid = f.pid
     yield(f)