[Bug libstdc++/60401] stdlib.h does not provide abs(long) overload

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60401

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
If you include stdlib.h and not cstdlib it's a glibc bug, not a gcc/libstdc++
one.