Port: handle 'size_t' / 'off_t' on Solaris

Port: handle 'size_t' / 'off_t' on Solaris

The size of 'size_t' / 'off_t' vary on some platforms, use C99 portable
macros and print formats to handle them.

Print 'size_t' with '%zu' and use SIZE_MAX as max value.
Print 'off_t' casted to 'intmax_t' with '%jd'.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>