This tries to load vulkan.framework or libvulkan.1.dylib before MoltenVK.framework
or libMoltenVK.dylib. In the previous version, layers would not work for applications
run-time loading the default library.
This work was done by Jacob Lifshay and Mark Callow; I'm just merging it
into revision control.
--HG--
extra : rebase_source : cb3bb332146125366b5242c0d7444f44638733d9
extra : amend_source : c72ebb6d3a92efc3fdd085ce3b6d4b1d7f573cc9