HaO: transfered from TCL

I updated Tcl to 8.6.9 on OpenIndiana 2018.10 (illumos kernel, an OpenSolaris fork) and noticed that SQLite 3.26.0 TCL test suite fails in some 30 cases, 27 of them fail like this:

! window1-13.5 expected: [
]
! window1-13.5 got:      []

However, those 27 work with Tcl 8.6.7.

Here's the OpenIndiana shipped Tcl 8.6.7 sources:

Here are my Tcl 8.6.9 changes, which exhibit the problem:

You can run the SQLite test suite by `make test`, test cases are in tests/.

Here's the window1-13.5 test case from

590 do_execsql_test 13.5 {
591   SELECT a, rank() OVER(ORDER BY b) FROM t1
592     INTERSECT
593   SELECT a, rank() OVER(ORDER BY b DESC) FROM t1;
594 } {
595 }