Clean up various warnings in bionic.

Change-Id: Ic57541d0a567fd4ae79f0ad59b2ffde1130eb7d2
diff --git a/libc/upstream-netbsd/port_before.h b/libc/upstream-netbsd/port_before.h
index 5e06e52..23d99c2 100644
--- a/libc/upstream-netbsd/port_before.h
+++ b/libc/upstream-netbsd/port_before.h
@@ -19,6 +19,7 @@
 
 #include "namespace.h"
 #include <sys/cdefs.h>
+#include <time.h>
 #include "private/arpa_nameser.h"
 
 #define ISC_FORMAT_PRINTF(a,b) __printflike(a,b)