LLVMgold vs. liblto_plugin for ar

Folks,

is there any documentation that explains the differences, strengths,
advantages, etc., between the `LLVMgold.so' plugin for `ar' and
`liblto_plugin.so' from gcc?

On my openSuSE GNU/Linux box, a link to the former is installed by
default in `/usr/lib/bfd-plugins', while I have to create a link for
the latter if I want to use it (using ar's `--plugin' option, or
removing the link to `LLVMgold.so').

    Werner