* ext/-test-/popen_deadlock/infinite_loop_dlsym.c: new ext to call
dlsym(3) infinitely without GVL, used in the above test.
* ext/-test-/popen_deadlock/extconf.rb: extconf.rb for the above
ext. Currently, only enabled on Solaris (main target) and Linux
(as a reference platform and for debugging the ext).
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51030 b2dd03c8-39d4-4d8f-98ff-823fe69b080e