Nested `startTransition` call "takes over" and makes parent `startTransition` unable to track `isPending`.

Seb says it's a bug.

Repro:

https://codesandbox.io/s/pensive-breeze-rg70wn?file=/IndexPage.js:192-288

1. Click the button
2. `isPending` in `IndexPage.js` is `true`

However, `isPending` in `App.js` is `false`.

Expected: `isPending` in `App.js` is also `true`.
}
    }
  }
}
function checkDepsAreArrayDev(deps: mixed): void {
  if (__DEV__) {
    if (deps !== undefined && deps !== null && !isArray(deps)) {
      
      
      console.error(
        '%s received a final argument that is not an array (instead, received `%s`). When ' +
          'specified, the final argument must be an array.',
        currentHookNameInDev,
        typeof deps,
      );
    }
  }
}
function warnOnHookMismatchInDev(currentHookName: HookType): void {
  if (__DEV__) {
    const componentName = getComponentNameFromFiber(currentlyRenderingFiber);
    if (!didWarnAboutMismatchedHooksForComponent.has(componentName)) {
      didWarnAboutMismatchedHooksForComponent.add(componentName);
      if (hookTypesDev !== null) {
        let table = '';
        const secondColumnStart = 30;
        for (let i = 0; i <= ((hookTypesUpdateIndexDev: any): number); i++) {
          const oldHookName = hookTypesDev[i];
          const newHookName =
            i === ((hookTypesUpdateIndexDev: any): number)