mark Alloc as an omittable operation if result isn't used
mark Alloc as an omittable operation if result isn't used

Ignore-this: 4a2d1ba0f08b4ac3468f716b3031f669

darcs-hash:20120117083846-1a7c6-b47b212358ebcf7f613ccdbe9c0315e9bc298923

jimcrayne/jhc,jimcrayne/jhc,jimcrayne/jhc,jimcrayne/jhc