dlopen vs. libstdc++, need entry in FAQ?

[Benjamin Kosnik]

> Hmmm.  In those PR's, you're recommending -rdynamic, which isn't
> documented anywhere.  From grepping the specs and the compiler config
> dirs, I can see that it just remaps into --export-dynamic for the linker. 
> But does that assume/require the GNU linker? 

I don't know. It is what 'man dlopen' recommends though, so I thought I'd 
stick it in. Seems to work, but I don't know if it's necessary.

-benjamin