[Bug lto/89166] -static prevents liblto_plugin to be created

[ilg at livius dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89166

--- Comment #1 from Liviu Ionescu <ilg at livius dot net> ---
a related bug is https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84995