fetch with Request init with body of FormData is broken

[johnspurlock]

FormData set as the body: BodyInit of the RequestInit passed to the Request constructor should behave the same way as the body: BodyInit of the RequestInit as the second arg to fetch(input, init)

Currently it doesn't, sending a request body with the text [object FormData]

const formData = new FormData();
formData.append('foo', 'bar');
const res = await fetch(new Request('http://example.com', { method: 'POST', body: formData }));
// request.text() on the server side will be "[object FormData]", request.formData() will be empty

deno 1.8.2 (release, x86_64-apple-darwin)
v8 9.0.257.3
typescript 4.2.2