bug#13260: 24.3.50; save match data for core functions like `delete-char' and`delete-backward-char'?

[Drew Adams]

> 99% of the functions can destroy the match-data, even though they
> may preserve it in 99% of the circumstances.  And in 99% of the
> cases where they do destroy the match-data, nobody cares anyway,
> which is why we shouldn't always save-match-data.

This is well put, and helpful.  How about saying something similar in the Elisp
manual?  It provides a good guideline for understanding when you might want to
save match data.