Add stub visitor support for ir_texture.
diff --git a/ir_constant_expression.cpp b/ir_constant_expression.cpp
index 361a7a1..e89b5bc 100644
--- a/ir_constant_expression.cpp
+++ b/ir_constant_expression.cpp
@@ -67,6 +67,7 @@
    virtual void visit(ir_function_signature *);
    virtual void visit(ir_function *);
    virtual void visit(ir_expression *);
+   virtual void visit(ir_texture *);
    virtual void visit(ir_swizzle *);
    virtual void visit(ir_dereference_variable *);
    virtual void visit(ir_dereference_array *);
@@ -503,6 +504,15 @@
 
 
 void
+ir_constant_visitor::visit(ir_texture *ir)
+{
+   // FINISHME: Do stuff with texture lookups
+   (void) ir;
+   value = NULL;
+}
+
+
+void
 ir_constant_visitor::visit(ir_swizzle *ir)
 {
    (void) ir;