http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58710
--- Comment #1 from Misty De Meo <misty at brew dot sh> --- It looks like the check was added in a4a5a77adfc9c28d6963e5ae054c997d57cfc7fa (http://repo.or.cz/w/official-gcc.git/commitdiff/a4a5a77adfc9c28d6963e5ae054c997d57cfc7fa), which didn't touch the existing behaviour that was already doing some definition of whether _Unwind_GetIPInfo was available or not.
