Delay resolution of library symbols until runtime.
Delay resolution of library symbols until runtime.

This is needed for dynamic libraries on OS X. This was supposed to be
part of #647, but it was left out.

keunwoo/coreutils,Heather/coreutils,jbcrail/coreutils,retep998/coreutils,Arcterus/coreutils,keunwoo/coreutils,mauricio/coreutils,beni55/coreutils,Arcterus/coreutils,tempbottle/coreutils,kevgeniy/coreutils,silvio/rust-coreutils,dennis/coreutils,steveklabnik/coreutils,wimh/coreutils,silvio/rust-coreutils,beni55/coreutils,hexsel/coreutils,sshling/coreutils,steveklabnik/coreutils,filmor/coreutils,mauricio/coreutils,Shir0kamii/coreutils,dennis/coreutils,Heather/coreutils,uutils/coreutils,dbrgn/coreutils,efuquen/coreutils,ebfe/coreutils,samfoo/coreutils,kwantam/coreutils,uutils/coreutils,efuquen/coreutils,Shir0kamii/coreutils,kball/coreutils,tempbottle/coreutils,wimh/coreutils,uutils/coreutils,dbrgn/coreutils,Shtong/coreutils,kevgeniy/coreutils,dbrgn/coreutils,kball/coreutils,kwantam/coreutils,jbcrail/coreutils,bundai223/coreutils,samfoo/coreutils,ebfe/coreutils,retep998/coreutils,sshling/coreutils,hexsel/coreutils,filmor/coreutils,bundai223/coreutils,Shtong/coreutils