Fix typos in comments.

Backpatch to all supported versions, where applicable, to make backpatching
of future fixes go more smoothly.

Josh Soref

Discussion: https://www.postgresql.org/message-id/CACZqfqCf+5qRztLPgmmosr-B0Ye4srWzzw_mo4c_8_B_mtjmJQ@mail.gmail.com

src/backend/optimizer/util/joininfo.c

@@ -24,7 +24,7 @@
  *		Detect whether there is a joinclause that involves
  *		the two given relations.
  *
- * Note: the joinclause does not have to be evaluatable with only these two
+ * Note: the joinclause does not have to be evaluable with only these two
  * relations.  This is intentional.  For example consider
  *		SELECT * FROM a, b, c WHERE a.x = (b.y + c.z)
  * If a is much larger than the other tables, it may be worthwhile to

src/backend/optimizer/util/restrictinfo.c

@@ -550,7 +550,7 @@ join_clause_is_movable_into(RestrictInfo *rinfo,
 							Relids currentrelids,
 							Relids current_and_outer)
 {
-	/* Clause must be evaluatable given available context */
+	/* Clause must be evaluable given available context */
 	if (!bms_is_subset(rinfo->clause_relids, current_and_outer))
 		return false;