Have the xBestIndex method of the generate_series virtual table ignore contraints on the "value" column with usable=0.

FossilOrigin-Name: f5113a2ef84831ad2da723fa7e29e0d575e74e10585741ff51db8c2e37332cd2

test/tabfunc01.test

@@ -348,6 +348,29 @@ do_execsql_test tabfunc01-920 {
   ) LIMIT -1 OFFSET 0;
 } {1 2 3 4 5 6 7 8 9 10 101 102 103 104}
 
+#-------------------------------------------------------------------------
+# Forum post https://sqlite.org/forum/forumpost/e7c3ae1215
+#
+foreach {tn where res} {
+  1000 "where value = 2" 2
+  1010 "where value in (2)" 2
+  1020 "where value in (select 2)" 2
+  1030 "where value = 2 OR value = 4" {2 4}
+  1040 "where value in (2, 4)" {2 4}
+} {
+  do_execsql_test $tn "
+    SELECT value FROM generate_series(1, 5) $where
+  " $res
+}
+
+do_execsql_test 1100 {
+  select 1 as c_0
+    from        
+    generate_series(1, 1) as ref_3
+    where (ref_3.value) in (select 1);
+} {1}
+
+
 
 # Free up memory allocations
 intarray_addr