bc: fix handling of "digits" above 9

function                                             old     new   delta
zxc_lex_next                                        1573    1608     +35
xc_parse_pushIndex                                    58      56      -2
xc_program_index                                      71      63      -8
zxc_program_num                                     1022     990     -32
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/3 up/down: 35/-42)             Total: -7 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
3 files changed