glsl ir: add as_dereference_record

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/glsl/ir.h

@@ -120,6 +120,7 @@ public:
    virtual class ir_dereference *       as_dereference()      { return NULL; }
    virtual class ir_dereference_array *	as_dereference_array() { return NULL; }
    virtual class ir_dereference_variable *as_dereference_variable() { return NULL; }
+   virtual class ir_dereference_record *as_dereference_record() { return NULL; }
    virtual class ir_expression *        as_expression()       { return NULL; }
    virtual class ir_rvalue *            as_rvalue()           { return NULL; }
    virtual class ir_loop *              as_loop()             { return NULL; }
@@ -1738,6 +1739,11 @@ public:
 
    virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
 
+   virtual ir_dereference_record *as_dereference_record()
+   {
+      return this;
+   }
+
    /**
     * Get the variable that is ultimately referenced by an r-value
     */