Add check for shm_open() since these functions quite often are located in librt
Add check for shm_open() since these functions quite often are located in librt

troxor/umurmur,snowblind/umurmur,doctaweeks/umurmur,doctaweeks/umurmur,fmorgner/umurmur,troxor/umurmur,fmorgner/umurmur,snowblind/umurmur,doctaweeks/umurmur