Auto merge of #405 - mmun:patch-1, r=alexcrichton
Auto merge of #405 - mmun:patch-1, r=alexcrichton

Add getchar_unlocked and putchar_unlocked

Adds [getchar_unlocked](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getchar_unlocked.html) and [putchar_unlocked](http://pubs.opengroup.org/onlinepubs/9699919799/functions/putchar_unlocked.html).

cactorium/libc,cactorium/libc,anatol/libc,mneumann/libc,rust-lang-nursery/libc,rust-lang/libc,philippkeller/libc,zethra/libc,cactorium/libc,mneumann/libc,superriva/libc,rust-lang/libc,philippkeller/libc,superriva/libc,anatol/libc,zethra/libc,rust-lang/libc,anatol/libc,mneumann/libc,superriva/libc,rust-lang-nursery/libc,zethra/libc,philippkeller/libc,rust-lang-nursery/libc