Squashed 'ffi-mini/' changes from e0505aa..93b804c

72049b1 libffi v3.0.14-rc0-WIP4: zwaldowski/libffi-iOS@fbb0bae
93b804c Fix broken #ifdef

git-subtree-dir: ffi-mini
git-subtree-split: 93b804cbaa5c856f5ffa53d137baa4c859b13a21