Treat template overload set correctly
fix Issue 8352 - Wrong "__overloadset isn't a template" error
Add test for Issue 9235 - Template mixin doesn't allow to mixin non-conflicting overloads
+1 ti::tempdecls
+2 ti::tempdecls
--cleanup 1st stage (Phobos build&test OK)
Issue 9235 2nd test
-remove debug prints
+error handling
+stash