Further refactoring of the ORDER BY related query-planning logic in order

to make it easier to extend to support optimizing out ORDER BY on joins.
No actual behavior changes, yet.

FossilOrigin-Name: 96496ddae12a239b30a1fc997fbea43e3a75bfe7

src/sqliteInt.h

@@ -1906,7 +1906,8 @@ struct SrcList {
 */
 struct WherePlan {
   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
-  u32 nEq;                       /* Number of == constraints */
+  u16 nEq;                       /* Number of == constraints */
+  u16 nOBSat;                    /* Number of ORDER BY terms satisfied */
   double nRow;                   /* Estimated number of rows (for EQP) */
   union {
     Index *pIdx;                   /* Index when WHERE_INDEXED is true */