Tests/CXXModules: add a test using TARGET_OBJECTS from modules

See: #25732

Tests/RunCMake/CXXModules/RunCMakeTest.cmake

@@ -220,6 +220,7 @@ if ("named" IN_LIST CMake_TEST_MODULE_COMPILATION)
   unset(RunCMake_CXXModules_NO_TEST)
   run_cxx_module_test(same-src-name)
   run_cxx_module_test(scan_properties)
+  run_cxx_module_test(target-objects)
 endif ()
 
 # Tests which require compile commands support.

Tests/RunCMake/CXXModules/examples/target-objects/CMakeLists.txt

@@ -0,0 +1,22 @@
+cmake_minimum_required(VERSION 3.28)
+project(cxx_modules_target_objects CXX)
+
+include("${CMAKE_SOURCE_DIR}/../cxx-modules-rules.cmake")
+
+add_library(target_objects)
+target_sources(target_objects
+  PRIVATE
+    FILE_SET CXX_MODULES
+      BASE_DIRS
+        "${CMAKE_CURRENT_SOURCE_DIR}"
+      FILES
+        importable.cxx)
+target_compile_features(target_objects PRIVATE cxx_std_20)
+
+add_executable(main)
+target_sources(main
+  PRIVATE
+    main.cxx
+    "$<TARGET_OBJECTS:target_objects>")
+
+add_test(NAME main COMMAND main)

Tests/RunCMake/CXXModules/examples/target-objects/importable.cxx

@@ -0,0 +1,13 @@
+export module importable;
+
+export int from_import()
+{
+  return 0;
+}
+
+extern "C++" {
+int f()
+{
+  return from_import();
+}
+}

Tests/RunCMake/CXXModules/examples/target-objects/main.cxx

@@ -0,0 +1,6 @@
+int f();
+
+int main(int argc, char* argv[])
+{
+  return f();
+}