Refactoring of DISTINCT code.  Change the name of the local variable
"distinct" to "distinctTab".  Generate cleaner code w/o unnecessary P4
and P5 values on the OP_Null for WHERE_DISTINCT_ORDERED.

FossilOrigin-Name: 0cda241a2bcb3c6f2ae6c48f522780bc4eddfc02
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 9d8d742..00aa480 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2059,7 +2059,7 @@
 ** as the OP_OpenEphm instruction is coded because not
 ** enough information about the compound query is known at that point.
 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
-** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
+** for the result set.  The KeyInfo for addrOpenEphm[2] contains collating
 ** sequences for the ORDER BY clause.
 */
 struct Select {