"I believe I did, Bob."

I'm being more than a bit mean here, in my attempt to be slightly amusing, because there's actually an obvious workaround: dynamically link with the LGPL library, like people usually do, and then it's nice and easy. The sort of systems where this would be difficult are the sort of systems where actually distributing a GPL program is just going to be annoying anyway, and you're probably better off not even trying.

But it is actually an interesting idea! I assume for the average program you'd be including more of your symbol information than you might like, though, as object files have to find their external symbols somehow! (I imagine LTCG will add a lot of additional information as well. All this would add up to a lot of useful info that would assist in the sort of reverse-engineering effort that proprietary software vendors would like to make more tedious, rather than less so.)

But, if you really wanted to do it, and didn't mind putting a bit of effort in, you could probably do something. An enormous non-LTCG translation unit containing all of the code, probably.