test/pdiff/pdiff.c uses non portable code which fails on various platforms.

Here is a simple patch to make cairo work on solaris, tru64 and hp-ux:

--- test/pdiff/pdiff.c.old
+++ test/pdiff/pdiff.c
@@ -20,7 +20,15 @@
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
+
+#ifdef sun
+#include <sys/int_types.h>
+#elif defined (__osf__)
+#include <inttypes.h>
+#elif !defined (__hpux__)
 #include <stdint.h>
+#endif
+
 #include "pdiff.h"

 #ifndef M_PI