feat(furc/parser): add function calls

furc/src/main.cpp

@@ -8,6 +8,7 @@ int main(void) {
     std::string_view content = R"(
         func main(argc: u64) -> s32 pre(arc > 1) {
             x: s32 = 1 + 2 * 3;
+            println(x);
             return if (x == 9) 1 else 0;
         }
     )";