Whilst it is somewhat late in the day to be suggesting changes to avast 2016, considering it is already in beta testing. This usually means it is feature/function locked.
Files aren't just tested against their given file type.
Since files are scanned prior to their execution, it shouldn't matter what the file name is but its action. You will also notice that in the File System Shield settings Scan when opening and Scan when writing, there is already an option to Scan all files.