bug#71289: 30.0.50; cmcheckmagic aborts when tty_write_glyphs writes "Garbage collecting..." in some cases

[Eli Zaretskii]

> From: Daniel Clemente <n142857@gmail.com>
> Date: Thu, 6 Jun 2024 15:23:33 +0000
> Cc: 71289@debbugs.gnu.org
> 
> Right now if I run the C-x 2 and resize scenario, I get this other
> backtrace with build_frame_matrix_from_leaf_window, it's not the one
> you requested (the one in check_matrix_pointers), but does it help?
> This is with your latest patch.

When you do "C-x 2", does Emacs divide the root window horizontally or
vertically?  Are the windows one above the other or are they side by
side?