This is the default OpenGL format, and in fact the only pixel format
that GLES supports uploading as. Actually, the premultiplied part is
really just about how we use the textures, but all textures in GTK
are premultiplied.
The calls used old bugzilla URLs and nobody cared about that.
So apparently they are very unused.
There's also a potential conflict between gitlab and bugzilla URLs and
what base bug to use there.
The old usages have been converted to comments.
