CREATE INDEX: do not update stats during binary upgrade.

During binary upgrade, indexes are created before the data is moved
into place, so it will always be zero.

This is not currently a major problem, but will be when we try to
preserve statistics during upgrade.

Author: Corey Huinker
Discussion: https://postgr.es/m/CADkLM=daPdFB8V0tgFxK-dLowFsAEzWRWJHyxij7BG3kBjcouA@mail.gmail.com

src/backend/catalog/index.c

@@ -2874,7 +2874,11 @@ index_update_stats(Relation rel,
 		dirty = true;
 	}
 
-	if (reltuples >= 0)
+	/*
+	 * Avoid updating statistics during binary upgrade, because the indexes
+	 * are created before the data is moved into place.
+	 */
+	if (reltuples >= 0 && !IsBinaryUpgrade)
 	{
 		BlockNumber relpages = RelationGetNumberOfBlocks(rel);
 		BlockNumber relallvisible;