[Bug other/58996] [4.9 regression] build failure in libcilkrts

[PHHargrove at lbl dot gov]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58996

--- Comment #5 from Paul H. Hargrove <PHHargrove at lbl dot gov> ---
The patch in comment #2 allows the build to complete without the need to
--disable-libcilkrts.  However, I agree with Jakub (comment #3) that use of a
glibc internal macros is a poor idea and a configure-time check is prefered. 
Just because __cpu_set_t_defined exists today doesn't mean it will continue to
exist in later glibc revisions.