libc: Fix headers to allow direct inclusion.

These headers are missing a few #includes to allow their direct
inclusion from C

http://b.android.com/79841

Change-Id: Ifc712c17f4da70b26adb67d4d49ed659f53c3621

libc/include/android/dlext.h

@@ -18,7 +18,9 @@
 #define __ANDROID_DLEXT_H__
 
 #include <stddef.h>
+#include <stdint.h>
 #include <sys/cdefs.h>
+#include <sys/types.h>  /* for off64_t */
 
 __BEGIN_DECLS
 

libc/include/fts.h

@@ -35,6 +35,8 @@
 #ifndef	_FTS_H_
 #define	_FTS_H_
 
+#include <sys/types.h>
+
 typedef struct {
 	struct _ftsent *fts_cur;	/* current node */
 	struct _ftsent *fts_child;	/* linked list of children */
@@ -111,8 +113,6 @@ typedef struct _ftsent {
 	char fts_name[1];		/* file name */
 } FTSENT;
 
-#include <sys/cdefs.h>
-
 __BEGIN_DECLS
 FTSENT	*fts_children(FTS *, int);
 int	 fts_close(FTS *);

libc/include/sys/user.h

@@ -31,6 +31,7 @@
 
 #include <sys/cdefs.h>
 #include <limits.h> /* For PAGE_SIZE. */
+#include <stddef.h> /* For size_t. */
 
 __BEGIN_DECLS