Auto merge of #889 - EdSchouten:cloudabi-time_t, r=alexcrichton
Auto merge of #889 - EdSchouten:cloudabi-time_t, r=alexcrichton

Add time_t for CloudABI.

Even though this data type is not used by libstd in any platform
independent code, one of the unit tests in src/libstd/time/mod.rs refers
to it. Instead of making that unit test more complicated, simply add
time_t, matching the type used by the C library.

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