Configure: add check for type

Configure: add check for type

Based on autoscan report:

configure.ac: warning: missing AC_TYPE_INT16_T wanted by: formats/ctf/types/integer.c:111
configure.ac: warning: missing AC_TYPE_INT32_T wanted by: formats/ctf/types/integer.c:120
configure.ac: warning: missing AC_TYPE_INT64_T wanted by: lib/trace-collection.c:111
configure.ac: warning: missing AC_TYPE_INT8_T wanted by: formats/ctf/types/integer.c:103
configure.ac: warning: missing AC_TYPE_OFF_T wanted by: formats/ctf/ctf.c:863
configure.ac: warning: missing AC_TYPE_SSIZE_T wanted by: lib/iterator.c:51
configure.ac: warning: missing AC_TYPE_UINT16_T wanted by: formats/ctf/types/integer.c:71
configure.ac: warning: missing AC_TYPE_UINT32_T wanted by: converter/babeltrace-log.c:127
configure.ac: warning: missing AC_TYPE_UINT64_T wanted by: lib/iterator.c:52
configure.ac: warning: missing AC_TYPE_UINT8_T wanted by: converter/babeltrace-log.c:141

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>