libc::O_SYNC is not re-exported

[carllerche]

It does not seem that O_SYNC has been re-exported by libc

[steveklabnik]

There are now pub consts for the variants of this.

$ git grep O_SYNC
src/etc/libc.c:#ifdef O_SYNC
src/etc/libc.c:  put_const(O_SYNC, int);
src/liblibc/lib.rs:            pub const O_SYNC : c_int = 1052672;
src/liblibc/lib.rs:            pub const O_SYNC : c_int = 16400;
src/liblibc/lib.rs:            pub const O_SYNC : c_int = 128;
src/liblibc/lib.rs:            pub const O_SYNC : c_int = 128;