anv: enable VK_EXT_shader_stencil_export

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/intel/vulkan/anv_pipeline.c

@@ -152,6 +152,7 @@ anv_shader_compile_to_nir(struct anv_pipeline *pipeline,
          .subgroup_quad = true,
          .subgroup_shuffle = true,
          .subgroup_vote = true,
+         .stencil_export = device->instance->physicalDevice.info.gen >= 9,
       },
    };