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**Do you want to request a *feature* or report a *bug*?**
bug, I believe, unless I misunderstand how it works
**What is the current behavior?**
Given a `Suspense` inside `Suspense` case like
```
<Suspense fallback="Fallback 1">
  <LazyText1 text="First text" />
  <Suspense fallback="Fallback 2">
    <LazyText2 text="Second text!" />
  </Suspense>
</Suspense>
```

Promises in `LazyTexts` start resolving at the same time, but if `LazyText2` is resolved first it never renders, `Fallback 2` stays.

Result:
```
First text

Fallback 2
```

Please see https://codesandbox.io/s/234o4zry7n

**What is the expected behavior?**

Every `LazyText` displayed in the end
```
First text

Second text!
```

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
react, react-dom 16.6.0

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */
import type {Fiber} from './ReactFiber';
import type {FiberRoot} from './ReactFiberRoot';
import type {ExpirationTime} from './ReactFiberExpirationTime';
import type {CapturedValue} from './ReactCapturedValue';
import type {Update} from './ReactUpdateQueue';
import type {Thenable} from './ReactFiberScheduler';
import type {SuspenseState} from './ReactFiberSuspenseComponent';
import {unstable_wrap as Schedule_tracing_wrap} from 'scheduler/tracing';
import getComponentName from 'shared/getComponentName';
import warningWithoutStack from 'shared/warningWithoutStack';
import {
  ClassComponent,
  HostRoot,
  HostComponent,
  HostPortal,
  ContextProvider,
  SuspenseComponent,
  IncompleteClassComponent,
} from 'shared/ReactWorkTags';
import {
  DidCapture,
  Incomplete,