Rename BLI_make_existing_file to BLI_file_ensure_parent_dir_exists. The previous name read as if it would make (touch) the file, where as it ensures the directory component of the path exists. Move from BLI_path to BLI_fileops as path utilities should only manipulate paths and not deal with file IO creation (this has more in common with BLI_file_touch for e.g.).