comipiling

----
const PM_QS_INPUT =         QS_INPUT;
const QS_INPUT =           2;
----

produces:
test.d(1): Error: forward reference of variable QS_INPUT

Here's a patch:

Index: expression.c
===================================================================
--- expression.c	(revision 421)
+++ expression.c	(working copy)
@@ -2395,7 +2395,9 @@
     {
 	//printf("Identifier '%s' is a variable, type '%s'\n", toChars(), v->type->toChars());
 	if (!type)
-	{   type = v->type;
+	{   if (!v->type && v->scope)
+		v->semantic(v->scope);
+	    type = v->type;
 	    if (!v->type)
 	    {	error("forward reference of %s %s", v->kind(), v->toChars());
 		type = Type::terror;