Step next should respect do/while condition block.

src/x64/codegen-x64.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1300 matching lines @@
         node->break_target()->Bind();
       }
       break;
     case DONT_KNOW:
       // We have to compile the test expression if it can be reached by
       // control flow falling out of the body or via continue.
       if (node->continue_target()->is_linked()) {
         node->continue_target()->Bind();
       }
       if (has_valid_frame()) {
+        Comment cmnt(masm_, "[ DoWhileCondition");
+        CodeForDoWhileConditionPosition(node);
         ControlDestination dest(&body, node->break_target(), false);
         LoadCondition(node->cond(), &dest, true);
       }
       if (node->break_target()->is_linked()) {
         node->break_target()->Bind();
       }
       break;
   }
 
   DecrementLoopNesting();
@@ skipping 6504 matching lines @@
   masm.GetCode(&desc);
   // Call the function from C++.
   return FUNCTION_CAST<ModuloFunction>(buffer);
 }
 
 #endif
 
 #undef __
 
 } }  // namespace v8::internal