Fixed: #2322 More AS3 Assigment position when using dup

libsrc/ffdec_lib/testdata/as3_new/src/Main.as

@@ -100,6 +100,7 @@ package
         TestOperations;
         TestOptimization;
         TestOptimizationAndOr;
+        TestOptimizationWhile;
         TestOptionalParameters;
         TestParamNames;
         TestParamsCount;

libsrc/ffdec_lib/testdata/as3_new/src/tests/TestOptimizationWhile.as

@@ -0,0 +1,29 @@
+package tests
+{
+	
+	public class TestOptimizationWhile
+	{
+		public function run():*
+		{
+            // Add more than 3 variables. 
+            // Optimization happens from register 4 on.
+            // (setlocal X takes more bytes than dup)
+			var a:int = 1;
+            var b:int = 2;
+            var c:int = 3;
+            
+            var d:int = 4;
+            
+            while(true)
+             {
+                d = Math.round(Math.random() * 10);
+                if(d >= 10)
+                {
+                   break;
+                }
+                trace("xxx");
+                d++;
+             } 
+		}
+	}
+}