See #17798
CONCURRENT_MODE_SYMBOL_STRING: string,
  DEPRECATED_ASYNC_MODE_SYMBOL_STRING: string,
  CONTEXT_CONSUMER_NUMBER: number,
  CONTEXT_CONSUMER_SYMBOL_STRING: string,
  CONTEXT_PROVIDER_NUMBER: number,
  CONTEXT_PROVIDER_SYMBOL_STRING: string,
  FORWARD_REF_NUMBER: number,
  FORWARD_REF_SYMBOL_STRING: string,
  MEMO_NUMBER: number,
  MEMO_SYMBOL_STRING: string,
  PROFILER_NUMBER: number,
  PROFILER_SYMBOL_STRING: string,
  STRICT_MODE_NUMBER: number,
  STRICT_MODE_SYMBOL_STRING: string,
  SCOPE_NUMBER: number,
  SCOPE_SYMBOL_STRING: string,
|};
type ReactPriorityLevelsType = {|
  ImmediatePriority: number,
  UserBlockingPriority: number,
  NormalPriority: number,
  LowPriority: number,
  IdlePriority: number,
  NoPriority: number,
|};
type ReactTypeOfWorkType = {|
  ClassComponent: number,
  ContextConsumer: number,
  ContextProvider: number,
  CoroutineComponent: number,