#version 450
#extension GL_EXT_buffer_reference2 : require

// Forward-declared buffer_reference block whose body is never defined, then used
// in pointer arithmetic. The referent stays an empty member list, so the block
// size is 0.
layout(buffer_reference) buffer B;

layout(local_size_x = 1) in;
void main()
{
    B b;
    b = b + 1;
}