hush: explain run_list() in detail; small optimizations

function                                             old     new   delta
hush_main                                            785     786      +1
expand_variables                                    1447    1448      +1
builtin_exit                                          48      49      +1
builtin_eval                                          54      55      +1
run_list                                            2075    2055     -20
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(add/remove: 0/0 grow/shrink: 4/1 up/down: 4/-20)             Total: -16 bytes

1 file changed