unotest: backport CPPUNIT_TEST_FIXTURE macro from cppunit.git

Added upstream as
<https://cgit.freedesktop.org/libreoffice/cppunit/commit/?id=48145587c4c2dc4f1e07d83073e136336c81ce79>.

Change-Id: If3adbad3187e3d2b4319be7b295b41d5b7e9c08d
Reviewed-on: https://gerrit.libreoffice.org/62975
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

include/unotest/bootstrapfixturebase.hxx

@@ -22,6 +22,21 @@
 #include <unotest/detail/unotestdllapi.hxx>
 #include <unotest/directories.hxx>
 
+// For cppunit < 1.15.0.
+#ifndef CPPUNIT_TEST_FIXTURE
+#define CPPUNIT_TEST_FIXTURE(TestClass, TestName)                              \
+    class TestName : public TestClass                                          \
+    {                                                                          \
+    public:                                                                    \
+        void TestBody();                                                       \
+        CPPUNIT_TEST_SUITE(TestName);                                          \
+        CPPUNIT_TEST(TestBody);                                                \
+        CPPUNIT_TEST_SUITE_END();                                              \
+    };                                                                         \
+    CPPUNIT_TEST_SUITE_REGISTRATION(TestName);                                 \
+    void TestName::TestBody()
+#endif
+
 namespace test {
 
 // Class to do lots of heavy-lifting UNO & environment