Xvfb render node/glamor support
This MR exactly what it says on the tin - adds glamor support for Xvfb.
In the process of doing so, it removes the xf86 specifics from glamor_egl (glamor_xv still needs work). Then using it for Xvfb, while making possible Xwayland to drop it's glamor_egl-like implementation. But that for another day.
Current MR works like a charm with glxinfo, glxgears, waffle and apitrace.
Some nitpicks for later series:
- double-check the pixmap wrapping and fix any violations Revert the two NULL check patches and go to town.
- split and cleanup glamor vs dri3 -
i915 barfs a
DRM_IOCTL_I915_GEM_CONTEXT_DESTROY failed: Bad file descriptor - make the node name configurable Env. variable is ugly, Xvfb has no config file support... cmdline argument?