test_queue.rb: fix portability

* test/thread/test_queue.rb (test_queue_with_trap): fix
  portability.  use SIGINT instead of SIGUSR2 which is supported
  on not all platforms.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57492 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/thread/test_queue.rb

@@ -549,14 +549,14 @@ class TestQueue < Test::Unit::TestCase
   end
 
   def test_queue_with_trap
-    assert_in_out_err([], <<-INPUT, %w(USR2 USR2 exit), [])
+    assert_in_out_err([], <<-INPUT, %w(INT INT exit), [])
       q = Queue.new
-      trap(:USR2){
-        q.push 'USR2'
+      trap(:INT){
+        q.push 'INT'
       }
       Thread.new{
         loop{
-          Process.kill :USR2, $$
+          Process.kill :INT, $$
         }
       }
       puts q.pop