vrend,features: Report PIPE_PRIM_PATCHES when tesselation is supported

On pre-4.0 GL hosts that support tesselation this is needed, because
otherwise, when the guest issues a patch primitive mesa/gallium will
assert.

Closes: #31

Fixes:
    Various piglits from texturesize/tes-texturesize*

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>

src/vrend_renderer.c

@@ -7894,7 +7894,7 @@ static void vrend_renderer_fill_caps_v1(int gl_ver, int gles_ver, union virgl_ca
                             (1 << PIPE_PRIM_TRIANGLES_ADJACENCY) |
                             (1 << PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY);
    }
-   if (caps->v1.glsl_level >= 400)
+   if (caps->v1.glsl_level >= 400 || has_feature(feat_tessellation))
       caps->v1.prim_mask |= (1 << PIPE_PRIM_PATCHES);
 
    if (epoxy_has_gl_extension("GL_ARB_vertex_type_10f_11f_11f_rev")) {