Further fixed (in branch text-elided) 'text count -ypixels' with indices in elided lines, since previous fixes such as [30d6b995dc] were not correct in all cases (sigh!).

Test case 'K':
--------------

package require Tk
pack [text .t]
for {set i 1} {$i < 25} {incr i} {
    .t insert end [string repeat "Line $i -" 10]
    .t insert end "\n"
}
.t debug on
wm geometry . 200x200+0+0
.t tag add hidden 5.36 11.0
.t tag configure hidden -elide true
.t yview 5.0
update
.t count -ypixels 5.0 11.0  ; # returns : 0 ; correct : 16 (1 line)