bug#59678: [PATCH] sh-script: use completion-table-with-cache to improve performance

[Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

>> I found that the auto-completion on .sh files (with company-mode) was
>> pretty slow (takes several seconds).  It turns out that company-mode
>> would call the capf function with 'metadata action for each
>> candidate, where each function call would need to list all the
>> cmds. In this patch, I modified the code to use
>> completion-table-with-cache which fixes the problem for me.
>
> Stefan, any comments?

Looks OK to me.  The description of the problem looks concerning, tho:
if Company really calls the completion table with `metadata` once per
candidate, then there's a bug in company.


        Stefan