Fix @match with __typename: other in MatchContainer

Reviewed By: kassens

Differential Revision: D23747302

fbshipit-source-id: a91727b30be1b1a65fdbc9743a6a25a58d96f1e5

Author: tyao1

packages/relay-experimental/MatchContainer.js

@@ -86,6 +86,7 @@ const {useMemo} = React;
 
 // Note: this type is intentionally non-exact, it is expected that the
 // object may contain sibling fields.
+type TypenameOnlyPointer = {|+__typename: string|};
 export type MatchPointer = {
   +__fragmentPropName?: ?string,
   +__module_component?: mixed,
@@ -96,7 +97,7 @@ export type MatchPointer = {
 export type MatchContainerProps<TProps: {...}, TFallback: React.Node> = {|
   +fallback?: ?TFallback,
   +loader: (module: mixed) => React.AbstractComponent<TProps>,
-  +match: ?MatchPointer,
+  +match: ?MatchPointer | ?TypenameOnlyPointer,
   +props?: TProps,
 |};