Turn on wasm flags all the time, add a reference from wasm functions to the module.

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index 3a933dd32f6dd362e2a7afa2d0cb5d55c471d3ab..cbbc192ca36ec2f690a284e17377dcaf537daeeb 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -1214,6 +1214,8 @@ Handle<JSFunction> Factory::NewFunction(Handle<Map> map,
       map.is_identical_to(
           isolate()->sloppy_function_with_readonly_prototype_map()) ||
       map.is_identical_to(isolate()->strict_function_map()) ||
+      (FLAG_expose_wasm &&
+       map.is_identical_to(isolate()->wasm_function_map())) ||
       map.is_identical_to(isolate()->proxy_function_map()));
   return NewFunction(map, info, context);
 }