[debug] Don't notify listener of exceptions internal to a desugaring.

src/ast/prettyprinter.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/ast/prettyprinter.h"
 
 #include <stdarg.h>
 
 #include "src/ast/ast-value-factory.h"
 #include "src/ast/scopes.h"
@@ skipping 879 matching lines @@
   switch (node->catch_prediction()) {
     case HandlerTable::UNCAUGHT:
       prediction = "UNCAUGHT";
       break;
     case HandlerTable::CAUGHT:
       prediction = "CAUGHT";
       break;
     case HandlerTable::PROMISE:
       prediction = "PROMISE";
       break;
+    case HandlerTable::DESUGARING:
+      prediction = "DESUGARING";
+      break;
   }
   Print(" %s\n", prediction);
 }
 
 void AstPrinter::VisitDebuggerStatement(DebuggerStatement* node) {
   IndentedScope indent(this, "DEBUGGER", node->position());
 }
 
 
 void AstPrinter::VisitFunctionLiteral(FunctionLiteral* node) {
@@ skipping 277 matching lines @@
 
 void AstPrinter::VisitRewritableExpression(RewritableExpression* node) {
   Visit(node->expression());
 }
 
 
 #endif  // DEBUG
 
 }  // namespace internal
 }  // namespace v8