Remove (near-)duplicate definitions of size_t and ssize_t.

The near duplicates upset fussier compilers that insist that
typedefs be exactly the same, but the fix isn't to make all
copies identical...

Change-Id: Icfdace41726f36ec33c9ae919dbb5a54d3529cc9
diff --git a/libc/include/stdio.h b/libc/include/stdio.h
index 20a9829..cd04d9c 100644
--- a/libc/include/stdio.h
+++ b/libc/include/stdio.h
@@ -39,30 +39,11 @@
 #define	_STDIO_H_
 
 #include <sys/cdefs.h>
-#include <sys/_types.h>
+#include <sys/types.h>
 
 #include <stdarg.h>
 #include <stddef.h>
 
-#if __BSD_VISIBLE || __POSIX_VISIBLE || __XPG_VISIBLE
-#include <sys/types.h>	/* XXX should be removed */
-#endif
-
-#ifndef _SIZE_T_DEFINED_
-#define _SIZE_T_DEFINED_
-typedef unsigned int  size_t;
-#endif
-
-#ifndef _SSIZE_T_DEFINED_
-#define _SSIZE_T_DEFINED_
-typedef long int  ssize_t;
-#endif
-
-#ifndef	_OFF_T_DEFINED_
-#define	_OFF_T_DEFINED_
-typedef	long    off_t;
-#endif
-
 #define __need_NULL
 #include <stddef.h>