https://github.com/KhronosGroup/EGL-Registry/pull/95 has moved
a couple of extensions defines and functions to the upstream eglext.h,
but when 9a74746b sync'ed these files we broke compilation
of apps that require these symbols on systems that don't have the
updated Khronos headers.
On non-GLVND builds, we still provide these headers, so everything's fine, but on GLVND builds the Khronos headers are external so we need to make sure we have a libglvnd version that's recent enough.
Fixes: 9a74746b ("EGL: sync headers with Khronos")