KNOWNBUGS.rb: deferred free

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59126 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

KNOWNBUGS.rb

@@ -5,3 +5,13 @@
 # This test file includes tests which point out known bugs.
 # So all tests will cause failure.
 #
+
+assert_normal_exit("#{<<-";END;"}")
+begin
+  require "-test-/typeddata"
+rescue LoadError
+else
+  n = 1 << 20
+  Bug::TypedData.make(n)
+end
+;END;