Comment update for join pushdown.

Etsuro Fujita

src/backend/optimizer/util/pathnode.c

@@ -1449,13 +1449,13 @@ create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel,
 
 /*
  * create_foreignscan_path
- *	  Creates a path corresponding to a scan of a foreign table,
- *	  returning the pathnode.
+ *	  Creates a path corresponding to a scan of a foreign table or
+ *	  a foreign join, returning the pathnode.
  *
  * This function is never called from core Postgres; rather, it's expected
- * to be called by the GetForeignPaths function of a foreign data wrapper.
- * We make the FDW supply all fields of the path, since we do not have any
- * way to calculate them in core.
+ * to be called by the GetForeignPaths or GetForeignJoinPaths function of
+ * a foreign data wrapper.  We make the FDW supply all fields of the path,
+ * since we do not have any way to calculate them in core.
  */
 ForeignPath *
 create_foreignscan_path(PlannerInfo *root, RelOptInfo *rel,