reverted r419 since I don't see any way to implement the 10.5 semantics correctly
reverted r419 since I don't see any way to implement the 10.5 semantics correctly

liruqi/cocotron,mpw/marcelweiher-libobjc2,liruqi/cocotron,mpw/marcelweiher-libobjc2,berkus/cocotron,berkus/cocotron,berkus/cocotron,liruqi/cocotron,uptime-services/development-arts,uptime-services/development-arts,berkus/cocotron,uptime-services/development-arts,uptime-services/development-arts,mpw/marcelweiher-libobjc2,mpw/marcelweiher-libobjc2,liruqi/cocotron