Switch from @executable_path to @loader_path for macOS
Switch from @executable_path to @loader_path for macOS

This will make sure libraries can load other libraries via their rpaths.
@executable_path, obviously, only applies to the executable doing the
(possibly indirect) loading.

jimporter/bfg9000,jimporter/bfg9000,jimporter/bfg9000,jimporter/bfg9000