Prefer more specific functions to DtoResolveDsymbol.

The remaining ones should also be easy to remove with a
closer look at the situation.

Ideally, we would get rid of all of them at some point and
use safe wrapper functions for accessing the IrDsymbol
associated with a given declaration (which would emit the
declarations on the fly if not already present).

gen/declarations.cpp

@@ -50,7 +50,7 @@ void InterfaceDeclaration::codegen(Ir* p)
 
     if (members && symtab)
     {
-        DtoResolveDsymbol(this);
+        DtoResolveClass(this);
 
         // Emit any members (e.g. final functions).
         for (ArrayIter<Dsymbol> it(members); !it.done(); it.next())