Debugger: fix stepping next with trycatch recursion

src/debug.h

 // Copyright 2011 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 488 matching lines @@
 
     // Source statement position from last step next action.
     int last_statement_position_;
 
     // Number of steps left to perform before debug event.
     int step_count_;
 
     // Frame pointer from last step next action.
     Address last_fp_;
 
+    // Number of queued steps left to perform before debug event.
+    int queued_step_count_;
+
     // Frame pointer for frame from which step in was performed.
     Address step_into_fp_;
 
     // Frame pointer for the frame where debugger should be called when current
     // step out action is completed.
     Address step_out_fp_;
 
     // Storage location for jump when exiting debug break calls.
     Address after_break_target_;
 
@@ skipping 532 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(MessageDispatchHelperThread);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 #endif  // V8_DEBUG_H_