Auto merge of #876 - asomers:remove_deprecated, r=alexcrichton
Auto merge of #876 - asomers:remove_deprecated, r=alexcrichton

Change deprecated constants into hidden constants

rustc, an important libc consumer, has a policy that they can't use any
crates with deprecated symbols.  Replace libc's two deprecated symbols
with hidden symbols instead.

rust-lang/libc,rust-lang/libc,rust-lang-nursery/libc,rust-lang/libc,rust-lang-nursery/libc,rust-lang-nursery/libc