Embed manifest in test executable built with MinGW

The tests create long paths when they see that the Registry value for long path support is set, and the manifest is supposed to advertise that the executable supports long paths. However, when the Registry value is set, the tests fail whether the manifest is embedded or not.

I'm not sure if that's an issue with Wine, MinGW or what I've done.

cpp/cmake/tests.cmake

@@ -68,6 +68,8 @@ set(LIBLOOT_INTERFACE_TESTS_ALL_SOURCES
 
 if(MSVC)
     list(APPEND LIBLOOT_INTERFACE_TESTS_ALL_SOURCES "${PROJECT_SOURCE_DIR}/src/tests/libloot_tests.manifest")
+elseif(MINGW)
+    list(APPEND LIBLOOT_INTERFACE_TESTS_ALL_SOURCES "${PROJECT_SOURCE_DIR}/src/tests/resource.rc")
 endif()
 
 ##############################

cpp/src/tests/resource.rc

@@ -0,0 +1,13 @@
+#ifdef _WIN32
+
+#ifndef CREATEPROCESS_MANIFEST_RESOURCE_ID
+#define CREATEPROCESS_MANIFEST_RESOURCE_ID 1
+#endif
+
+#ifndef RT_MANIFEST
+#define RT_MANIFEST 24
+#endif
+
+CREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST "tests/libloot_tests.manifest"
+
+#endif