svga: issue debug warning for unsupported two-sided stencil state

We only have a single stencil read mask and write mask.  Issue a
warning if different front/back values are used.  The Piglit
gl-2.0-two-sided-stencil test hits this.

Reviewed-by: Neha Bhende <bhenden@vmware.com>
Reviewed-by: Charmaine Lee <charmainel@vmware.com>
1 file changed