Tests: Add t_interface_colon_bad (#5281)

test_regress/t/t_interface_colon_bad.out

@@ -0,0 +1,7 @@
+%Error: t/t_interface_colon_bad.v:14:7: Package/class for ':: reference' not found: 'iface'
+   14 |       iface::func();   
+      |       ^~~~~
+%Error: t/t_interface_colon_bad.v:14:14: Can't find definition of task/function: 'func'
+   14 |       iface::func();   
+      |              ^~~~
+%Error: Exiting due to

test_regress/t/t_interface_colon_bad.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('linter')
+
+test.lint(fails=True, expect_filename=test.golden_filename)
+
+test.passes()

test_regress/t/t_interface_colon_bad.v

@@ -0,0 +1,17 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2024 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+interface iface;
+   function static func;
+   endfunction
+endinterface
+
+module t;
+   initial begin
+      iface::func();  // BAD
+      $stop;
+   end
+endmodule