-The following private API functions had their context parameter removed,
-C<Perl_cast_ulong>, C<Perl_cast_i32>, C<Perl_cast_iv>, C<Perl_cast_uv>,
-C<Perl_cv_const_sv>, C<Perl_mg_find>, C<Perl_mg_findext>, C<Perl_mg_magical>,
-C<Perl_mini_mktime>, C<Perl_my_dirfd>, C<Perl_sv_backoff>, C<Perl_utf8_hop>.
-
-Users of the public API prefix-less calls remain unaffected.
+Added L<perlapi/sync_locale>.
+Changing the program's locale should be avoided by XS code. Nevertheless,
+certain non-Perl libraries called from XS, such as C<Gtk> do so. When this
+happens, Perl needs to be told that the locale has changed. Use this function
+to do so, before returning to Perl.