conversion of structs with multi-dim fields (resolves #53)

test/basic/struct_array_field.sv

@@ -0,0 +1,34 @@
+module main;
+    typedef struct packed {
+        logic [1:0][2:0] x;
+        logic [0:2][1:0] y;
+        logic z;
+    } foo_t;
+    foo_t foo;
+
+    initial begin
+        $monitor($time, " %b %b %b %b %b %b %b %b",
+            foo, foo.x, foo.y, foo.z,
+            foo.x[0], foo.x[0][0], foo.y[0], foo.y[0][0]);
+
+        #1; foo.z = 0;
+
+        #1; foo.y = 0;
+        #1; foo.y[0] = '1;
+        #1; foo.y[1] = '1;
+        #1; foo.y[1][1] = 0;
+        #1; foo.y[0][0] = 1;
+        #1; foo.y[0][1] = 1;
+
+        #1; foo.x = 0;
+        #1; foo.x[0] = '1;
+        #1; foo.x[1] = '1;
+        #1; foo.x[1][1] = 0;
+        #1; foo.x[0][0] = 1;
+        #1; foo.x[0][1] = 1;
+
+    end
+endmodule
+
+module top;
+endmodule