[deoptimizer] Do not pass arguments markers to the debugger.

src/deoptimizer.cc

 // Copyright 2013 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/v8.h"
 
 #include "src/accessors.h"
 #include "src/codegen.h"
 #include "src/cpu-profiler.h"
 #include "src/deoptimizer.h"
@@ skipping 2248 matching lines @@
   context_ = reinterpret_cast<Object*>(output_frame->GetContext());
   has_construct_stub_ = has_construct_stub;
   expression_count_ = output_frame->GetExpressionCount();
   expression_stack_ = new Object* [expression_count_];
   // Get the source position using the unoptimized code.
   Address pc = reinterpret_cast<Address>(output_frame->GetPc());
   Code* code = Code::cast(deoptimizer->isolate()->FindCodeObject(pc));
   source_position_ = code->SourcePosition(pc);
 
   for (int i = 0; i < expression_count_; i++) {
-    SetExpression(i, output_frame->GetExpression(i));
+    Object* value = output_frame->GetExpression(i);
+    // Replace materialization markers with the undefined value.
+    if (value == deoptimizer->isolate()->heap()->arguments_marker()) {
+      value = deoptimizer->isolate()->heap()->undefined_value();
+    }
+    SetExpression(i, value);
   }
 
   if (has_arguments_adaptor) {
     output_frame = deoptimizer->output_[frame_index - 1];
     CHECK_EQ(output_frame->GetFrameType(), StackFrame::ARGUMENTS_ADAPTOR);
   }
 
   parameters_count_ = output_frame->ComputeParametersCount();
   parameters_ = new Object* [parameters_count_];
   for (int i = 0; i < parameters_count_; i++) {
-    SetParameter(i, output_frame->GetParameter(i));
+    Object* value = output_frame->GetParameter(i);
+    // Replace materialization markers with the undefined value.
+    if (value == deoptimizer->isolate()->heap()->arguments_marker()) {
+      value = deoptimizer->isolate()->heap()->undefined_value();
+    }
+    SetParameter(i, value);
   }
 }
 
 
 DeoptimizedFrameInfo::~DeoptimizedFrameInfo() {
   delete[] expression_stack_;
   delete[] parameters_;
 }
 
 
@@ skipping 1115 matching lines @@
       DCHECK(value_info->IsMaterializedObject());
 
       value_info->value_ =
           Handle<Object>(previously_materialized_objects->get(i), isolate_);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8