This patch will make the EGL renderer work on any EGL/GLESv2 driver
providing the EGL_WL_bind_wayland_display extensions.
Mesa used to declare provisional EGL_WL_bind_wayland_display directly
in <EGL/eglext.h>. Then, all unofficial extensions were moved to
<EGL/eglmesaext.h>, to have a cleaner implementation. See:
ab7bb10a2a
The extension was then approved at Khronos Group, and reached the
official <EGL/eglext.h>. See:
https://www.khronos.org/registry/EGL/extensions/WL/EGL_WL_bind_wayland_display.txtaa9b63f3ab
In order to make sure the renderer will work on any version of any
implementation providing the extension, only include the mesa-specific
header if it's present.
Signed-off-by: Julien Olivain <juju@cotds.org>