Use another font for some characters

[Alex Kost]

Hello, in Emacs 24.5.1 (and earlier) I can use this:

  (set-fontset-font "fontset-default" '(#x2190 . #x2195) "Symbola")

and this range of characters (which is the following arrows: ← ↑ → ↓ ↔
↕), is displayed using "Symbola" font.

However in Emacs 25, the same set-fontset-font call doesn't take any
visible effect – the arrow characters are still displayed with my
default font (Liberation Mono).

So is there a way to achieve what I want in Emacs 25, I mean is there a
way to specify another font for characters that are supported by a
default font?

I think the mentioned difference in Emacs versions was introduced by one
of the commits made for <http://bugs.gnu.org/20727>, but I'm not sure if
this is a bug, or I just miss something, thanks.

-- 
Alex