wrong "composes" if spread Flow exact helper function (`...$Exact<OtherProps>`)

[millermedeiros]

If I have code like:

import type {Props as BarProps} from 'Bar.react';

const Bar = require('Bar.react');

type Props = {|
  ...$Exact<BarProps>,
  somePropOverride: 'baz',
|};

class Foo extends React.Component<Props> {
  render() {
    return <Bar {...this.props} />;
  }
}

the composes field will include one item named "$Exact", which is weird... - I would expect it to include "Bar.react" (if it was smart enough to figure out that BarProps was used as Props on Bar.react) or at least leave the composes empty.

tested on v3.0.0-beta10