fix stupid bug introduced during refactoring

idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java

@@ -1504,7 +1504,6 @@ public class ExpressionCodegen extends JetVisitor {
                 throw new UnsupportedOperationException("don't know how to handle non-class types in as/as?");
             }
             Type type = typeMapper.mapType(jetType, OwnerKind.INTERFACE);
-            gen(expression.getLeft(), OBJECT_TYPE);
             generateInstanceOf(new Runnable() {
                         @Override
                         public void run() {

idea/testData/codegen/typeInfo/asInLoop.jet

@@ -0,0 +1,7 @@
+import java.io.*
+fun main(args: Array<String>) {
+  val reader = new BufferedReader(new InputStreamReader(System.`in`))
+  while(true) {
+    val cmd = reader.readLine() as String
+  }
+}

idea/tests/org/jetbrains/jet/codegen/TypeInfoTest.java

@@ -79,6 +79,11 @@ public class TypeInfoTest extends CodegenTestCase {
         assertNull(foo.invoke(null));
     }
 
+    public void testAsInLoop() throws Exception {
+        loadFile();
+        generateFunction();  // assert no exception
+    }
+
     private Runnable newRunnable() {
         return new Runnable() {
             @Override