Regression test for not adding RPATHs with `ld -r` (#809, #821)
Regression test for not adding RPATHs with `ld -r` (#809, #821)

- ld -r is only broken with rpaths on OSX; this tests that
  specific case.

- test should still work cross-platform.

tmerrick1/spack,EmreAtes/spack,tmerrick1/spack,matthiasdiener/spack,krafczyk/spack,LLNL/spack,TheTimmy/spack,tmerrick1/spack,LLNL/spack,krafczyk/spack,iulian787/spack,TheTimmy/spack,mfherbst/spack,mfherbst/spack,mfherbst/spack,krafczyk/spack,lgarren/spack,krafczyk/spack,matthiasdiener/spack,EmreAtes/spack,skosukhin/spack,iulian787/spack,krafczyk/spack,matthiasdiener/spack,EmreAtes/spack,lgarren/spack,tmerrick1/spack,LLNL/spack,lgarren/spack,skosukhin/spack,TheTimmy/spack,iulian787/spack,matthiasdiener/spack,skosukhin/spack,skosukhin/spack,EmreAtes/spack,TheTimmy/spack,mfherbst/spack,LLNL/spack,lgarren/spack,mfherbst/spack,lgarren/spack,skosukhin/spack,iulian787/spack,LLNL/spack,matthiasdiener/spack,tmerrick1/spack,iulian787/spack,TheTimmy/spack,EmreAtes/spack