Extend the SQLITE_TESTCTRL_OPTIMIZATIONS option to disable DISTINCT
optimizations.

FossilOrigin-Name: 18501dd1a8aa8299c091c36e35b9a10a29d4467b
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index c1e055b..9f47ffd 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -956,6 +956,7 @@
 #define SQLITE_GroupByOrder   0x20        /* Disable GROUPBY cover of ORDERBY */
 #define SQLITE_FactorOutConst 0x40        /* Disable factoring out constants */
 #define SQLITE_IdxRealAsInt   0x80        /* Store REAL as INT in indices */
+#define SQLITE_DistinctOpt    0x80        /* DISTINCT using indexes */
 #define SQLITE_OptMask        0xff        /* Mask of all disablable opts */
 
 /*