Avoid redundant table b-tree cursor seeks in UPDATE statements that use the
two-pass strategy.

FossilOrigin-Name: dc555b1039c6930f6d15355c698ff917a85e8056
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 7ea8748..3f0da18 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2592,7 +2592,7 @@
 #define WHERE_SORTBYGROUP      0x0200 /* Support sqlite3WhereIsSorted() */
 #define WHERE_SEEK_TABLE       0x0400 /* Do not defer seeks on main table */
 #define WHERE_ORDERBY_LIMIT    0x0800 /* ORDERBY+LIMIT on the inner loop */
-                        /*     0x1000    not currently used */
+#define WHERE_SEEK_UNIQ_TABLE  0x1000 /* Do not defer seeks if unique */
                         /*     0x2000    not currently used */
 #define WHERE_USE_LIMIT        0x4000 /* Use the LIMIT in cost estimates */
                         /*     0x8000    not currently used */