Fix erroneous query result when RVC is clipped with desc column

       CREATE TABLE  test
       (
            pk1 INTEGER NOT NULL ,  
            pk2 INTEGER NOT NULL, 
            pk3 INTEGER NOT NULL, 
            pk4 INTEGER NOT NULL, 
            v INTEGER, CONSTRAINT PK PRIMARY KEY(pk1,pk2,pk3 desc,pk4))
       )

       UPSERT INTO test (pk1, pk2, pk3, pk4, v) VALUES (1,3,4,10,1)

     select * from test
     where (pk1 >=1 and pk1<=2) and (pk2>=3 and pk2<=4) and (pk3,pk4) < (5,7)

257                        List<KeyRange> leftRanges = clipLeft(schema, slot.getPKPosition()
258                            + slotOffset - clipLeftSpan, clipLeftSpan, keyRanges, ptr);
259                    keyRanges =
260                            clipRight(schema, slot.getPKPosition() + slotOffset - 1, keyRanges,
261                                    leftRanges, ptr);
262                    if (prevSortOrder == SortOrder.DESC) {
263                        leftRanges = invertKeyRanges(leftRanges);
264                    }
265                    slotSpanArray[cnf.size()] = clipLeftSpan-1;
266                    cnf.add(leftRanges);
267                    clipLeftSpan = 0;
268                    prevSortOrder = sortOrder;
269                    // since we have to clip the portion with the same sort order, we can no longer
270                    // extract the nodes from the where clause
271                    // for eg. for the schema A VARCHAR DESC, B VARCHAR ASC and query
272                    //   WHERE (A,B) < ('a','b')
273                    // the range (* - a\xFFb) is converted to (~a-*)(*-b)
274                    // so we still need to filter on A,B
275                    stopExtracting = true;
276                }