Fix darwin build tags to match GLFW CMake defaults.
Fix darwin build tags to match GLFW CMake defaults.

This fixes Retina support.

gonutz/glfw,jonbuckley33/glfw3,jonbuckley33/glfw3,go-gl/glfw,go-gl/glfw,go-gl/glfw,james4k/glfw,james4k/glfw,gonutz/glfw