!239 (merged) adds support for adding new EGLDeviceEXT handles, and adds handling so that
eglQueryDisplayAttribEXT(EGL_DEVICE_EXT) will update libglvnd's (device -> vendor) mapping.
But, I forgot to also add support for
eglQueryDisplayAttribNV. So, this change adds the other two suffixes.
That includes both handling the
EGL_DEVICE_EXT attribute for all three, and handling a vendor library that doesn't support the EXT version.