Add RTLD_NEXT and RTLD_SELF to *BSD

src/unix/bsd/mod.rs

@@ -275,7 +275,9 @@ pub const WNOHANG: ::c_int = 0x00000001;
 pub const WUNTRACED: ::c_int = 0x00000002;
 
 pub const RTLD_NOW: ::c_int = 0x2;
+pub const RTLD_NEXT: *mut ::c_void = -1isize as *mut ::c_void;
 pub const RTLD_DEFAULT: *mut ::c_void = -2isize as *mut ::c_void;
+pub const RTLD_SELF: *mut ::c_void = -3isize as *mut ::c_void;
 
 pub const LOG_CRON: ::c_int = 9 << 3;
 pub const LOG_AUTHPRIV: ::c_int = 10 << 3;