[Ada] Add a RM entry for the functional infinite sequences

[Pierre-Marie de Rodat via Gcc-patches]

Modify the RM to take into account the new functional container.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

        * doc/gnat_rm/the_gnat_library.rst: Add the new entry.
        * gnat_rm.texi: Regenerate.

patch.diff.gz
Description: application/gzip