[Bug d/94609] FAIL: gdc.dg/runnable.d

[ibuclaw at gdcproject dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94609

--- Comment #4 from Iain Buclaw <ibuclaw at gdcproject dot org> ---
(In reply to H.J. Lu from comment #2)
> 
> RDI/EDI isn't used to pass argument.  Is this done on purpose?  Where does
> D frontend decide how to pass argument?

Ultimately the main deciding factor is whether or not the type is marked
TREE_ADDRESSABLE.  That triggers NRVO to be done on the return variable.