Function addSubtreeSuspenseContext

docs/external/js/react-dom.development.js:14637–14639

(parentContext, subtreeContext)

    return parentContext & SubtreeSuspenseContextMask | shallowContext;
  }
  function addSubtreeSuspenseContext(parentContext, subtreeContext) {
    return parentContext | subtreeContext;
  }
  function pushSuspenseContext(fiber, newContext) {
    push(suspenseStackCursor, newContext, fiber);
  }