Poke in the dark and see if bors+windows stops screaming

Author: oli-obk

src/librustc/ty/instance.rs

@@ -109,7 +109,9 @@ impl<'tcx> InstanceDef<'tcx> {
             return true
         }
         let codegen_fn_attrs = tcx.codegen_fn_attrs(self.def_id());
-        codegen_fn_attrs.requests_inline() || tcx.is_const_fn(self.def_id())
+        // need to use `is_const_fn_raw` since we don't really care if the user can use it as a
+        // const fn, just whether the function should be inlined
+        codegen_fn_attrs.requests_inline() || tcx.is_const_fn_raw(self.def_id())
     }
 }