Improved Windows ABI support

tests/programs/variables.q

@@ -6,10 +6,12 @@ main() {
 	e := 5
 	f := 6
 	g := 7
-	h := 8
 
-	assert a != b
-	assert c != d
-	assert e != f
-	assert g != h
+	assert a != 0
+	assert b != 0
+	assert c != 0
+	assert d != 0
+	assert e != 0
+	assert f != 0
+	assert g != 0
 }