bug#9943: 24.0.91; Abort in check_glyph_memory

[Stefan Monnier]

> Thanks, I installed the same fix in xfns.c.

All this code duplication is really a bore.  We should really create
a new file (say "dispfns.c") where we can consolidate common code from
xfns, nsfns, and w32fns.  A good start would be that whenever we have to
make the same fix at all 3 places, we rearrange the code locally to call
a new function in dispfns.c which would receive the common part where
the fix can then be applied.


        Stefan