busybox

hush: fix backslash and terminator handling in <<[-]["]heredoc["]

function                                             old     new   delta
parse_stream                                        2339    2395     +56
expand_pseudo_dquoted                                104     118     +14
parse_stream_dquoted                                 296     300      +4
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(add/remove: 0/0 grow/shrink: 3/0 up/down: 74/0)               Total: 74 bytes

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>