support default pattern unbased unsized port bindings

src/Convert/UnbasedUnsized.hs

@@ -188,6 +188,8 @@ convertExpr _ (Cast te e) =
     Cast te $ convertExpr SelfDetermined e
 convertExpr _ (Concat exprs) =
     Concat $ map (convertExpr SelfDetermined) exprs
+convertExpr context (Pattern [(":default", e @ UU{})]) =
+    convertExpr context e
 convertExpr _ (Pattern items) =
     Pattern $ zip
     (map fst items)

test/basic/unbased_unsized_default.sv

@@ -0,0 +1,11 @@
+module Example(inp);
+    input [4][5] inp;
+    initial #1 $display("%b", inp);
+endmodule
+
+module top;
+    Example e1('{default:'0});
+    Example e2('{default:'1});
+    Example e3('{default:'x});
+    Example e4('{default:'z});
+endmodule

test/basic/unbased_unsized_default.v

@@ -0,0 +1,11 @@
+module Example(inp);
+    input [19:0] inp;
+    initial #1 $display("%b", inp);
+endmodule
+
+module top;
+    Example e1({20 {1'sb0}});
+    Example e2({20 {1'sb1}});
+    Example e3({20 {1'sbx}});
+    Example e4({20 {1'sbz}});
+endmodule