Special behaviour for _Dmodule_ref and _d_run_main?

[Denis Feklushkin]

Hi!

I am trying to build app & druntime from sources with -flto 
enabled and faced with this linker error:

ld.lld: error: undefined symbol: _Dmodule_ref
>>> referenced by app.d
>>>               lto.tmp:(.text._D3app16__moduleinfoCtorZ+0x0)
>>> referenced by app.d
>>>               lto.tmp:(_D3app16__moduleinfoCtorZ)


ld.lld: error: undefined symbol: _d_run_main
>>> referenced by entrypoint.d:35 
>>> (/usr/lib/ldc/x86_64-linux-gnu/include/d/core/internal/entrypoint.d:35)

It seems that link-time optimization discards these characters as 
unused.

I tried to add @assumeUsed into definitions, but it is not helps.

What can be ways to solve this problem?

Maybe LDC implements some special behaviour for _Dmodule_ref and 
_d_run_main?