SystemVerilog support for implicit named port connections

This is the `foo foo(.port1, .port2);` SystemVerilog syntax
introduced in IEEE1800-2005.

tests/various/implicit_ports.sv

@@ -0,0 +1,19 @@
+// Test implicit port connections
+module alu (input [2:0] a, input [2:0] b, input cin, output cout, output [2:0] result);
+	assign cout = cin;
+	assign result = a + b;
+endmodule
+
+module named_ports(output [2:0] alu_result, output cout);
+	wire [2:0] a = 3'b010, b = 3'b100;
+	wire cin = 1;
+
+	alu alu (
+		.a(a),
+		.b, // Implicit connection is equivalent to .b(b)
+		.cin(), // Explicitely unconnected
+		.cout(cout),
+		.result(alu_result)
+	);
+endmodule
+