cli: Adjust integer range check, replace magic numbers with constants
The value (1ULL << 63) - 1), used for checking that integer values are
within range, actually mean INT64_MAX, so use that instead.
Also, the negative case is not quite right: the value -(INT64_MAX + 1),
-
9223372036854775808, is within the range of a signed 64-bits number
(assuming two's complement), but is not accepted right now. Adjust the
check so it accepts that value.
I tested this patch manually: we accept -
9223372036854775808 but reject
-
9223372036854775809.
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>