bug#57160: 28.1.91; Info Virtual Index fails on search "two column"

[Juri Linkov]

> Inside Emacs at  the infopage for Emacs, the search  term "two column"
> finds   no   result,  the   search   term   "column"  finds   in   the
> "Info Virtual Index" the result:
>
>  . 2C-two-columns [Command Index]: Two-Column.
>
> Steps to reproduce
>
>  . start "emacs -Q"
>  . open Emacs's infopage by "F1 i" and navigating to entry for Emacs
>  . search index using "I" and type "two column"
>  . echo area says "No 'two column' in index"
>
> Expected result finds
>
>  . 2C-two-columns [Command Index]: Two-Column.

Everything works fine when you type "I two-column".