Fixed #2231 AS3 coercion to String as convert

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

@@ -107,6 +107,7 @@ package
         TestSlots;
         TestSlots2;
         TestStrictEquals;
+        TestStringCoerce;
         TestStringConcat;
         TestStrings;        
         TestSwitch;

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

@@ -0,0 +1,14 @@
+package tests
+{
+	
+	public class TestStringCoerce
+	{
+        var a:Object = null;
+    
+		public function run():*
+		{
+			var text1:String = this.a["test"];
+            var text2:String = String(this.a["test"]);
+		}
+	}
+}