fix: expose required symbol using clang (#5700)

* test: Added test case for visibility of common symbols across shared libraries

* style: pre-commit fixes

* tests: cmake target name fix

* tests: Added visibility test to ci

* tests: set the default visibility to hidden

* prototype/proof-of-concept fix: PYBIND11_EXPORT_GUARDED_DELETE

* Fix silly oversight: actually use PYBIND11_EXPORT_GUARDED_DELETE

* Update struct_smart_holder.h

* style: pre-commit fixes

* Update include/pybind11/detail/struct_smart_holder.h

* Update struct_smart_holder.h

* ci: fix addition to reusable-standard.yml

* Update CMakeLists.txt

* refactor: rename tests to test_cross_module_rtti

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rgrossekunst@nvidia.com>

tests/test_cross_module_rtti/catch.cpp

@@ -0,0 +1,22 @@
+// The Catch implementation is compiled here. This is a standalone
+// translation unit to avoid recompiling it for every test change.
+
+#include <pybind11/embed.h>
+
+// Silence MSVC C++17 deprecation warning from Catch regarding std::uncaught_exceptions (up to
+// catch 2.0.1; this should be fixed in the next catch release after 2.0.1).
+PYBIND11_WARNING_DISABLE_MSVC(4996)
+
+// Catch uses _ internally, which breaks gettext style defines
+#ifdef _
+#    undef _
+#endif
+
+#define CATCH_CONFIG_RUNNER
+#include <catch.hpp>
+
+int main(int argc, char *argv[]) {
+    pybind11::scoped_interpreter guard{};
+    auto result = Catch::Session().run(argc, argv);
+    return result < 0xff ? result : 0xff;
+}