As far as I know 'glamor' has been integrated in xorg-server starting with x11-base/xorg-server-1.16.0. However xf86-video-ati-7.4.0 is forcing external x11-libs/glamor to be built. This should be also the case with xf86-video-ati-7.3.0 I suppose.. Reproducible: Always
Wrong. >=x11-base/xorg-server-1.16.0 has 'glamor' useflag - it's simply package.use.masked last time I've checked.