Fix missing includes, again.

Test: mma
Bug: None
Change-Id: I17f07e51ebb425ebbcd2cd48e2aa173ab728c498
diff --git a/libc/bionic/spawn.cpp b/libc/bionic/spawn.cpp
index 7015ad9..3588d02 100644
--- a/libc/bionic/spawn.cpp
+++ b/libc/bionic/spawn.cpp
@@ -28,9 +28,11 @@
 
 #include <spawn.h>
 
+#include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 #include "private/ScopedSignalBlocker.h"