bug#3179: Entering Chinese "zero": add U+3007

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Mon, 14 Oct 2019 23:13:57 +0200
> Cc: 3179@debbugs.gnu.org, jidanni@jidanni.org
> 
> > Only Handa-san knows I guess... That's not the only strange
> > thing about leim/quail in general and leim-ext in particular, but I
> > didn't want to go there. (I just checked for other occurences of WHITE
> > CIRCLE vs IDEOGRAPHIC ZERO, and tested my change.)
> 
> Thanks; I've now applied the patch, and I'm now closing this bug report.

I don't understand this decision.  None of us knows enough about these
particular characters to tell U+25CB was a mistake (it was there since
day one of leim-ext.el), and the OP asked for _addition_ of U+3007.
So why did we replace instead of adding?