support for interface based typedefs

test/basic/interface_based_typedef.sv

@@ -0,0 +1,18 @@
+interface intf_i;
+    typedef int data_t;
+endinterface
+
+module sub(intf_i p, intf_i q [2]);
+    typedef p.data_t p_data_t; // interface based typedef
+    typedef q[0].data_t q_data_t; // interface based typedef
+    p_data_t p_data;
+    q_data_t q_data;
+    initial $display("p %0d %b", $bits(p_data), p_data);
+    initial $display("q %0d %b", $bits(q_data), q_data);
+endmodule
+
+module top;
+    intf_i p();
+    intf_i q[2]();
+    sub s(p, q);
+endmodule

test/basic/interface_based_typedef.v

@@ -0,0 +1,4 @@
+module top;
+    initial $display("p %0d %b", 32, 32'bx);
+    initial $display("q %0d %b", 32, 32'bx);
+endmodule