As part of MDL-72991, method build_course_cache now casts $course to be an instance of stdClass, however constructor of course_modinfo is not that strict.  That may cause some issue e.g. https://github.com/catalyst/moodle_tool_blocksmanager/issues/28

We should either: 

• cast stdClass for $course in the constructor;
• validate $course in the constructor and throw and exception;
• remove casting stdClass for $course in build_course_cache