Need clarification on dmd symbol generation

[Dicebot]

I am currently investigating 
http://d.puremagic.com/issues/show_bug.cgi?id=9571 and after 
brief exploration of symbols emitted to object file as well as 
code that emits them I can't rid of an idea that I am missing 
something about module system.

Why does dmd emits horde of symbols from imported modules into 
object files, most of whose are not actually used in this one? No 
"-inline" used and I kind of expected to see there only directly 
called function and symbols from their signatures.

What does actually happen here?