bug#25685: fill-paragraph vs. \n vs. Chinese / English boundaries

["積丹尼 Dan Jacobson" <jidanni@jidanni.org>]

Big problem!
Put the cursor upon the following paragraph,

We proceeded to dig up 些 some Canna edulis Ker 食用美人蕉
when surprise surprise...

and do

M-h (translated from <escape> h) runs the command mark-paragraph
(found in global-map), which is an interactive compiled Lisp function
in ‘paragraphs.el’.

then

M-q (translated from <escape> q) runs the command fill-paragraph
(found in global-map), which is an interactive compiled Lisp function
in ‘fill.el’.

It becomes

We proceeded to dig up 些 some Canna edulis Ker 食用美人蕉when
surprise surprise...

I.e., the "食用美人蕉when" are now stuck together, making our text
look very unprofessional.

You might argue that that's the way the ball bounces. But then I would
say what about "up 些 some", you didn't glue that together, and on
only one side (when removing "\n") either.

So what do I want? This:

We proceeded to dig up 些 some Canna edulis Ker 食用美人蕉 when
surprise surprise...