Problem:- When setting max_binlog_stmt_cache_size=18446744073709547520
from either command line or .cnf file, server fails to start.

Solution:- Added one more function eval_num_suffix_ull , which uses
strtoull to get unsigned ulonglong from string. And getopt_ull calls this
function instead of eval_num_suffix. Also changed previous eval_num_suffix to
eval_num_suffix_ll to remain consistent.