[test][js-api] WebAssembly.Exception.length should be 2

See https://webassembly.github.io/spec/js-api/#exceptions
> constructor(Tag exceptionTag, sequence<any> payload,
>             optional ExceptionOptions options = {});

Author: Liedtke

test/js-api/exception/constructor.tentative.any.js

@@ -10,7 +10,7 @@ test(() => {
 }, "name");
 
 test(() => {
-  assert_function_length(WebAssembly.Exception, 1, "WebAssembly.Exception");
+  assert_function_length(WebAssembly.Exception, 2, "WebAssembly.Exception");
 }, "length");
 
 test(() => {