Fix parsing caching

Flipped conditional meant that we were never caching the parse results :(

src/codegen/parser.cpp

@@ -1135,7 +1135,7 @@ AST_Module* caching_parse_file(const char* fn) {
     assert(code == 0);
     code = stat(cache_fn.c_str(), &cache_stat);
     std::vector<char> file_data;
-    if (code != 0 && (cache_stat.st_mtime > source_stat.st_mtime
+    if (code == 0 && (cache_stat.st_mtime > source_stat.st_mtime
                       || (cache_stat.st_mtime == source_stat.st_mtime
                           && cache_stat.st_mtim.tv_nsec > source_stat.st_mtim.tv_nsec))) {
         oss << "reading pyc file\n";