Ensure all relevant cache.diff options preserved in broadcastWatch.

Both `returnPartialData` and `canonizeResults` were missing from this
call. Instead of enumerating the properties, we can take advantage of
the overlap between `WatchOptions` and `DiffOptions` to pass all
properties through, without having to enumerate them explicitly, so this
kind of mistake won't happen again.

Fixes #8831.

src/cache/inmemory/inMemoryCache.ts

@@ -535,12 +535,17 @@ export class InMemoryCache extends ApolloCache<NormalizedCacheObject> {
     c: Cache.WatchOptions,
     options?: BroadcastOptions,
   ) {
-    const { lastDiff } = c;
-    const diff = this.diff<any>({
-      query: c.query,
-      variables: c.variables,
-      optimistic: c.optimistic,
-    });
+    const {
+      lastDiff,
+      // WatchOptions extends ReadOptions (adding a few fields like lastDiff),
+      // so the ...rest object of this destructuring is a ReadOptions object.
+      ...readOptions
+    } = c;
+
+    // DiffOptions also extends ReadOptions, and currently requires no extra
+    // properties, so we can use readOptions as DiffOptions, without having to
+    // enumerate the relevant properties (query, variables, etc.) explicitly.
+    const diff = this.diff<any>(readOptions);
 
     if (options) {
       if (c.optimistic &&