Squashed 'ffi-mini/' changes from 4c9f534..f6bf33c

f6bf33c libffi v3.0.14-rc0-WIP4: zwaldowski/libffi-iOS@fbb0bae
e0505aa libffi v3.0.14-rc0-WIP3: zwaldowski/libffi-iOS@45e0a3e
3cee33a libffi v3.0.14-rc0-WIP2: zwaldowski/libffi-iOS@6368781
775f4d6 libffi v3.0.14-rc0-WIP: zwaldowski/libffi-iOS@1020c1d
1fd81b7 libffi v3.0.14-rc0-WIP: zwaldowski/libffi-iOS@6b1ecfb
REVERT: 4c9f534 libffiv3.0.14-rc0-WIP: zwaldowski/libffi-iOS@1020c1d
REVERT: e4731ef libffiv3.0.14-rc0-WIP: zwaldowski/libffi-iOS@6b1ecfb

git-subtree-dir: ffi-mini
git-subtree-split: f6bf33cd542c4bac08059fc179c71963e63e0378
Update ffi-mini to zwaldowski/ffi-mini@f7bf33c