Fix some tests and do some cleanup.

test/parse/property_rename.golden

@@ -0,0 +1,11 @@
+(program	
+ (properties props
+  [(:= color float4)])
+
+ (fun vertex vs_main -> float4 (@position)
+  [(:= pos float4 (@position))] 
+  (return pos))
+
+ (fun pixel ps_main -> float4 (@target0)
+  [] 
+  (return props.color)))