Auto merge of #3244 - devnexen:redox__sigtimedwait, r=JohnTitor

redox add sig(timed)wait calls

Author: bors

libc-test/semver/redox.txt

@@ -215,6 +215,8 @@ reallocarray
 setpwent
 setrlimit
 setservent
+sigtimedwait
+sigwait
 strcasecmp
 strcasestr
 strlcat

src/unix/redox/mod.rs

@@ -1080,6 +1080,12 @@ extern "C" {
     ) -> ::c_int;
     pub fn pthread_cancel(thread: ::pthread_t) -> ::c_int;
     pub fn pthread_kill(thread: ::pthread_t, sig: ::c_int) -> ::c_int;
+    pub fn sigtimedwait(
+        set: *const sigset_t,
+        sig: *mut siginfo_t,
+        timeout: *const ::timespec,
+    ) -> ::c_int;
+    pub fn sigwait(set: *const sigset_t, sig: *mut ::c_int) -> ::c_int;
 
     // stdlib.h
     pub fn reallocarray(ptr: *mut ::c_void, nmemb: ::size_t, size: ::size_t) -> *mut ::c_void;