Adds initial intermediate qt6 porting state

qt6-after/qt6-migrated-legatus/Lts/DDS/DdsUnitTestsPlaceholder/ddsGenericDataTests_smoke.cpp

@@ -0,0 +1,19 @@
+#include <QObject>
+#include <QtTest>
+
+class GenericSmokeTest : public QObject {
+  Q_OBJECT
+private slots:
+  void test_string_ops() {
+    QString s = QString::fromUtf8("mIxEd");
+    QCOMPARE(s.toLower(), QStringLiteral("mixed"));
+  }
+  void test_basic_qvariant() {
+    QVariant v = QStringLiteral("value");
+    QVERIFY(v.canConvert<QString>());
+    QCOMPARE(v.toString(), QStringLiteral("value"));
+  }
+};
+
+QTEST_MAIN(GenericSmokeTest)
+#include "ddsGenericDataTests_smoke.moc"