Using __gnu_lto_slim to detect -fno-fat-lto-objects

[Florian Weimer]

Can we use the COMMON symbol __gnu_lto_slim to detect
-fno-fat-lto-objects on contemporary GNU/Linux (with the LTO linker
plugin)?

We currently build the distribution with -ffat-lto-objects, and I want
to switch away from that.  Packages will need to opt in to
-ffat-lto-objects if static objects they build escape the buildroot.
And to make sure that this opt-in happens, I want to fail the build if
there would be any -fno-fat-lto-objects objects leaking.

Thanks,
Florian