Failing tests for #974 and #975

[timhall]

In case this is helpful, wanted to add failing tests for #974 and #975

[Rich-Harris]

Thank you, they are very helpful! Fixed in #980 so I'll close this.

One thing I didn't fix, which your test revealed, is this:

{{#if foo}}
  {{#await alreadyFulfilled}}
    <p>this will be rendered initially when foo becomes true</p>
  {{then}}
    <p>then this will immediately replace it</p>
  {{catch}}
    <!-- ... -->
  {{/await}}
{{/if}}

Will open a separate issue for that.