A proposed fix for the DESC ORDER BY bug of ticket [4dd95f6943fbd18].

Seems to work, but lots more testing is needed prior to moving to trunk.

FossilOrigin-Name: 614a038ad2fe111687d2bc1c0aa716d7eb8fdd7c

src/sqliteInt.h

@@ -1931,6 +1931,7 @@ struct WherePlan {
   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
   u16 nEq;                       /* Number of == constraints */
   u16 nOBSat;                    /* Number of ORDER BY terms satisfied */
+  u16 iOBSat;                    /* First ORDER BY term satisfied */
   double nRow;                   /* Estimated number of rows (for EQP) */
   union {
     Index *pIdx;                   /* Index when WHERE_INDEXED is true */