* iconv/gconv_conf.c (insert_module): Take extra parameter to decide
whether the new record should be freed if it's a duplicate.
(add_module): Adjust insert_module call.
(__gconv_read_conf): Likewise.
* iconvdata/Makefile (generated): Add tst-loading.mtrace and
mtrace-tst-loading.
(tests): Make $(objpfx)mtrace-tst-loading a dependency. Add rule.