I want to clean up <ctype.h> now that API levels before 21 are no longer supported, but -- although upstream libc++ is fine -- our old libc++ unconditionally defines inlines for these functions, which collide with my attempt to do the same in bionic. Rather than keep waiting for the new libc++, backport this trivial fix. Test: treehugger Change-Id: I579a16ee3c4877d5033a0e4166f49d76af3a093b