C function to calculate the length of the CString to receive self

Property definitions

core :: abstract_text $ Byte :: byte_to_s_len
	# C function to calculate the length of the `CString` to receive `self`
	private fun byte_to_s_len: Int `{
		return snprintf(NULL, 0, "0x%02x", self);
	`}
lib/core/text/abstract_text.nit:1931,2--1934,3