Preserve exception message in iterator finalization.

src/full-codegen/full-codegen.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/full-codegen/full-codegen.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/ast-numbering.h"
 #include "src/ast/prettyprinter.h"
 #include "src/ast/scopeinfo.h"
@@ skipping 1265 matching lines @@
 
   // The try block adds a handler to the exception handler chain before
   // entering, and removes it again when exiting normally.  If an exception
   // is thrown during execution of the try block, the handler is consumed
   // and control is passed to the catch block with the exception in the
   // result register.
 
   Label try_entry, handler_entry, exit;
   __ jmp(&try_entry);
   __ bind(&handler_entry);
-  ClearPendingMessage();
+  if (stmt->clear_pending_message()) ClearPendingMessage();
 
   // Exception handler code, the exception is in the result register.
   // Extend the context before executing the catch block.
   { Comment cmnt(masm_, "[ Extend catch context");
     PushOperand(stmt->variable()->name());
     PushOperand(result_register());
     PushFunctionArgumentForContextAllocation();
     CallRuntimeWithOperands(Runtime::kPushCatchContext);
     StoreToFrameField(StandardFrameConstants::kContextOffset,
                       context_register());
@@ skipping 641 matching lines @@
   return var->mode() == CONST_LEGACY || var->scope()->is_nonlinear() ||
          var->initializer_position() >= proxy->position();
 }
 
 
 #undef __
 
 
 }  // namespace internal
 }  // namespace v8