xf86-video-ati-19.1.0 fails to build when glamor is disabled

Submitted by Alexander Tsoy @puleglot

Assigned to xf86-video-ati maintainers

Link to original bug (#112076)

Description

Downstream bug: https://bugs.gentoo.org/698114

If configured with --disable-glamor, xf86-video-ati fails to build with the following error:

radeon_present.c: In function ‘radeon_present_check_flip’:
radeon_present.c:281:21: error: dereferencing pointer to incomplete type ‘struct radeon_pixmap’
if (priv && priv->fb_failed)
^~

This is probably caused by [1] which was backported from xf86-video-amdgpu and requires glamor to be enabled.

[1] 33803c85