x11: Remove DRI2 support

DRI2 was hidden behind a legacy-x11 build option back in the 24.2
release. It's now been a year, so let's get on with removing it so we
can simplify our winsys interactions.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35885>

docs/egl.rst

@@ -153,8 +153,7 @@ EGL Drivers
    This driver supports several platforms: ``android``, ``device``,
    ``drm``, ``surfaceless``, ``wayland`` and ``x11``. It functions as
    a DRI driver loader. For ``x11`` support, it talks to the X server
-   directly using (XCB-)DRI3 protocol when available, and falls back to
-   DRI2 if necessary (can be forced with ``LIBGL_DRI3_DISABLE``).
+   directly using (XCB-)DRI3 protocol when available.
 
    This driver can share DRI drivers with ``libGL``.
 

docs/envvars.rst

@@ -26,14 +26,6 @@ LibGL environment variables
    if set to ``true``, do not use DrawArrays GLX protocol (for
    debugging)
 
-.. envvar:: LIBGL_DRI2_DISABLE
-
-   disable DRI2 if set to ``true``.
-
-.. envvar:: LIBGL_DRI3_DISABLE
-
-   disable DRI3 if set to ``true``.
-
 .. envvar:: LIBGL_KOPPER_DISABLE
 
    disable Vulkan swapchains with Zink if set to ``true``.

docs/relnotes/new_features.txt

@@ -63,3 +63,4 @@ timestamps on panvk/v10+
 VK_KHR_calibrated_timestamps on panvk/v10+
 VK_EXT_non_seamless_cube_map on panvk
 VK_ARM_shader_core_properties on panvk/v10+
+removed X11 DRI2 support