pc2line table only saves the diff between lines, so the function end
next line is needed to generate the function's last line diff, the
previous code missed it.
This patch fixed it by change the line number generate logic a bit.
This bug is found on https://github.com/koush/quickjs, an unofficial
debugger implementation, push it to the upstream.
Signed-off-by: pengyaozong <pengyaozong@xiaomi.com>