perl: Include <inttypes.h> and assume it always defines PRId64 and PRIu64.

If these are not defined in the header files, it's a problem on
the platform which we should fix with gnulib.  Our replacement
definitions might be wrong here.

generator/perl.ml

@@ -37,16 +37,14 @@ let rec generate_perl_xs () =
   pr "\
 #include <config.h>
 
+#include <inttypes.h>
+
 #include \"EXTERN.h\"
 #include \"perl.h\"
 #include \"XSUB.h\"
 
 #include <guestfs.h>
 
-#ifndef PRId64
-#define PRId64 \"lld\"
-#endif
-
 static SV *
 my_newSVll(long long val) {
 #ifdef USE_64_BIT_ALL
@@ -59,10 +57,6 @@ my_newSVll(long long val) {
 #endif
 }
 
-#ifndef PRIu64
-#define PRIu64 \"llu\"
-#endif
-
 static SV *
 my_newSVull(unsigned long long val) {
 #ifdef USE_64_BIT_ALL