improved testing of missing includes / made it possible to clear the include cache in simplecpp by firewave · Pull Request #4704 · cppcheck-opensource/cppcheck

This is necessary for the missing include tests to work.

This is not working properly if Cppcheck is being used to scan multiple projects within the same execution (e.g. when using it as a library).

This requires cppcheck-opensource/simplecpp#282 and cppcheck-opensource/simplecpp#287 merged first.