Add CLD_ constants

These constants appear in the si_code field of a SIGCHLD signal or
waitid-returned siginfo value.

Author: joshtriplett

src/unix/linux_like/mod.rs

@@ -1027,6 +1027,13 @@ pub const PIPE_BUF: usize = 4096;
 
 pub const SI_LOAD_SHIFT: ::c_uint = 16;
 
+pub const CLD_EXITED: ::c_int = 1;
+pub const CLD_KILLED: ::c_int = 2;
+pub const CLD_DUMPED: ::c_int = 3;
+pub const CLD_TRAPPED: ::c_int = 4;
+pub const CLD_STOPPED: ::c_int = 5;
+pub const CLD_CONTINUED: ::c_int = 6;
+
 pub const SIGEV_SIGNAL: ::c_int = 0;
 pub const SIGEV_NONE: ::c_int = 1;
 pub const SIGEV_THREAD: ::c_int = 2;