Fix mac sdk build.

Add include files for types and functions that were not included properly.

Change-Id: I4849f5bdf535c6eec9254228cf980c30d11a5a1b

include/cutils/threads.h

@@ -32,6 +32,7 @@ extern "C" {
 #if !defined(_WIN32)
 
 #include  <pthread.h>
+#include  <sys/types.h>
 
 typedef struct {
     pthread_mutex_t   lock;

libcutils/threads.c

@@ -21,6 +21,8 @@
 // For gettid.
 #if defined(__APPLE__)
 #include "AvailabilityMacros.h"  // For MAC_OS_X_VERSION_MAX_ALLOWED
+#include <stdint.h>
+#include <stdlib.h>
 #include <sys/syscall.h>
 #include <sys/time.h>
 #include <unistd.h>