Add lint error on importing package within a class

docs/CONTRIBUTORS

@@ -158,6 +158,7 @@ Nandu Raj
 Nathan Graybeal
 Nathan Kohagen
 Nathan Myers
+Nick Brereton
 Nolan Poe
 Oleh Maksymenko
 Patrick Stewart

src/V3LinkParse.cpp

@@ -895,6 +895,15 @@ class LinkParseVisitor final : public VNVisitor {
         }
         iterateChildren(nodep);
     }
+    void visit(AstClass* nodep) override {
+	cleanFileline(nodep);
+	for (AstNode* itemp = nodep->stmtsp(); itemp; itemp = itemp->nextp()) {
+	    if (VN_IS(itemp, PackageImport)) {
+		itemp->v3error("Import statement directly within a class scope is illegal");
+	    }
+	}
+	iterateChildren(nodep);
+    }
 
     void visit(AstNode* nodep) override {
         // Default: Just iterate

test_regress/t/t_class_scope_import.out

@@ -0,0 +1,4 @@
+%Error: t/t_class_scope_import.v:11:14: Import statement directly within a class scope is illegal
+   11 |    import pkg::*;
+      |              ^~
+%Error: Exiting due to

test_regress/t/t_class_scope_import.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 by Nick Brereton. 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_class_scope_import.v

@@ -0,0 +1,15 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2023 by Nick Brereton
+// SPDX-License-Identifier: CC0-1.0
+
+package pkg;
+endpackage
+
+class genericClass;
+   import pkg::*;
+endclass
+
+module tb_top();
+endmodule