Pass function sig in function_body::translate

src/tests.rs

@@ -13,6 +13,11 @@ fn execute_wat(wat: &str, a: usize, b: usize) -> usize {
     translated.execute_func(0, a, b)
 }
 
+#[test]
+fn empty() {
+    let _ = translate_wat("(module (func))");
+}
+
 #[test]
 fn adds() {
     const CASES: &[(usize, usize, usize)] = &[