OS X: Fix mpidistutils.config.check_library() to ignore undef symbols
OS X: Fix mpidistutils.config.check_library() to ignore undef symbols

pressel/mpi4py,mpi4py/mpi4py,mpi4py/mpi4py,mpi4py/mpi4py,pressel/mpi4py,pressel/mpi4py,pressel/mpi4py