Cannot import a file that has importcpp? Codegen issue?

[ggibson]

Hi, this looks like a codegen issue, but wanted to ask as I might be missing 
something simple. The code will only run if the type declaration is removed 
from the first file.

Tested on:

  * 0.16.1 (devel)
  * 0.16.0 (master)



File1: importme.nim 
    
    
    ## Random Device from C++
    type TRandomDevice*
    {.importcpp:"std::random_device", header:"<random>".} = object
    proc dothis*() =
       echo "ran the 'dothis' fn"
    

File2: main.nim 
    
    
    import importme
    dothis()
    

Clang Linker Error 
    
    
    Undefined symbols for architecture x86_64:                                  
                │~
      "_dothis_A9crgxPxoHyUlNFt9aA8PinQ", referenced from:                      
                │~
          _NimMainModule in testseq.o                                           
                │~
    ld: symbol(s) not found for architecture x86_64