Qiang Yu authored Jun 28, 2018 and Tomeu Vizoso committed Dec 19, 2018

Add __DRI2_RENDERER_EXPOSE_BUFFER_AGE dri integer query for
driver to determine if want to expose EGL/GLX_EXT_buffer_age.

Without knowing damage region first, some tile buffer based
GPU like ARM Mali Utgard has to load whole render target to
tile buffer before partitial update, then write them back.

Expose this extension will mis-lead application to use it
which will make performance worse for this kind of GPU.

EGL_KHR_partial_update is better choice for this kind of GPU.

Signed-off-by: Qiang Yu <yuq825@gmail.com>