Add in_port_t and move it and in_addr_t to the correct header file.

No one's reported this, but I saw it in an Android port of fuser(1).

We still have lots of problems in our network headers because we
get most of the structs direct from the kernel, and it doesn't use
types like this (which is why we've got away without this one for
so long). One day we should probably look at cleaning that up, but
doing so can wait.

Change-Id: If15edf0cfc32716fa312d7ed97c48321b760d979
diff --git a/libc/include/netinet/in.h b/libc/include/netinet/in.h
index bf3b498..44c7fc1 100644
--- a/libc/include/netinet/in.h
+++ b/libc/include/netinet/in.h
@@ -25,6 +25,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #ifndef _NETINET_IN_H_
 #define _NETINET_IN_H_
 
@@ -43,6 +44,9 @@
 
 #define INET_ADDRSTRLEN 16
 
+typedef uint16_t in_port_t;
+typedef uint32_t in_addr_t;
+
 extern int bindresvport (int sd, struct sockaddr_in *sin);
 
 static const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;