Replace template symbol module fix with more localized hack.

This reverts commit c4adbedcc, which would have fixed the
problem at its roots, but caused strange template function
attribute inference failures in D-YAML, presumably due to
the different order of semantic3 execution on the templates.

gen/todebug.cpp

@@ -35,7 +35,7 @@ using namespace llvm::dwarf;
 static Module* getDefinedModule(Dsymbol* s)
 {
     // templates are defined in current module
-    if (DtoIsTemplateInstance(s))
+    if (DtoIsTemplateInstance(s, true))
     {
         return gIR->dmodule;
     }