Experimental code-generator changes to utilize new opcodes for sorting.

FossilOrigin-Name: bab2e560f6cb989c83a96aad60f666960ede7abe

src/vdbeInt.h

@@ -59,6 +59,7 @@ struct VdbeCursor {
   Bool isTable;         /* True if a table requiring integer keys */
   Bool isIndex;         /* True if an index containing keys only - no data */
   Bool isOrdered;       /* True if the underlying table is BTREE_UNORDERED */
+  Bool isSorter;        /* True if a new-style sorter */
   sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
   const sqlite3_module *pModule;     /* Module for cursor pVtabCursor */
   i64 seqCount;         /* Sequence counter */