Fix selector name buffer not ending in NULL
Inhibit no-compact-unwind for tests
Fix IMP-casting warning
Squashed 'ffi-mini/' changes from 21b189e..a1dd29c

a1dd29c libffi v3.0.14-rc0-WIP5: zwaldowski/libffi-iOS@8ba9545

git-subtree-dir: ffi-mini
git-subtree-split: a1dd29ce267455a95ae6700c5e64980ff546d732
Fix arm64 void fallthrough, Xcode 5.1b5 warnings

Merge commit '6c3ac449202e0360744df018882ab9f264ef9b86' into next