small cleanup

src/org/jetbrains/jet/j2k/Converter.java

@@ -563,10 +563,13 @@ public class Converter {
   }
 
   private static boolean isReadOnly(@NotNull PsiParameter parameter) {
-    for (PsiReference r : (ReferencesSearch.search(parameter))) {
-      if (r instanceof PsiExpression && PsiUtil.isAccessedForWriting((PsiExpression) r)) {
-        return false;
+    try {
+      for (PsiReference r : (ReferencesSearch.search(parameter))) {
+        if (r instanceof PsiExpression && PsiUtil.isAccessedForWriting((PsiExpression) r)) {
+          return false;
+        }
       }
+    } catch (IllegalArgumentException ignored) {
     }
     return true;
   }

src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java

@@ -311,11 +311,11 @@ public class ExpressionVisitor extends StatementVisitor {
 
     Expression identifier = new IdentifierImpl(expression.getReferenceName(), isNullable);
 
-    final String temporaryObject = "__";
+    final String __ = "__";
     if (hasReceiver)
-      identifier = new CallChainExpression(new IdentifierImpl(temporaryObject, false), new IdentifierImpl(expression.getReferenceName(), isNullable));
+      identifier = new CallChainExpression(new IdentifierImpl(__, false), new IdentifierImpl(expression.getReferenceName(), isNullable));
     else if (insideSecondaryConstructor && isThis)
-      identifier = new IdentifierImpl("val " + temporaryObject + " = " + className); // TODO: hack
+      identifier = new IdentifierImpl("val __ = " + className); // TODO: hack
 
     myResult = new CallChainExpression(
       expressionToExpression(expression.getQualifierExpression()),