/*
=for apidoc bytes_from_utf8_loc
-Like C<L</bytes_from_utf8>()>, but takes an extra parameter, a pointer to where
-to store the location of the first character in C<"s"> that cannot be
+Like C<L<perlapi/bytes_from_utf8>()>, but takes an extra parameter, a pointer
+to where to store the location of the first character in C<"s"> that cannot be
converted to non-UTF8.
If that parameter is C<NULL>, this function behaves identically to