bug#59900: 30.0.50; map pattern in pcase causes a byte-compile error

[Akira Komamura <akira.komamura@gmail.com>]

After upgrading to Emacs 29, some packages throw byte-compile errors
due to use of `map' pattern in `pcase':

> org-bookmark-heading.el:176:6: Error: Unknown map pattern: (map
> 'filename 'outline-path 'id 'front-context-string 'indirectp)

The error can be avoided by `require'ing `map' at compile time in the
library depending on pcase:

(eval-when-compile
  ;; Support map pattern in pcase
  (require 'map))

However, this was not necessary in the previous versions.

As a similar example, the `rx' pattern for `pcase' is autoloaded (see
`rx.el'), so shouldn't the `map' pattern support be autoloaded as well?

;;;###autoload
(pcase-defmacro rx (&rest regexps)
  ...