nice to see AMD finally supporting GL_EXT_geometry_shader4 and other important extensions.
I think I've found a bug in the current Windows drivers (Catalyst 9.9): Call glEnable(GL_LINE_SMOOTH) when you use a geometry shader and your program will crash with an access violation. No crash occurs if the GPU program consists of vertex and fragment shader only. The app also doesn't crash on NVIDIA systems.
thanks for the report, we will investigate this issue.