Removing redundant stub for runtime native calls.

src/debug.cc

 // Copyright 2006-2008 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 57 matching lines @@
 
 static Handle<Code> ComputeCallDebugPrepareStepIn(int argc) {
   CALL_HEAP_FUNCTION(StubCache::ComputeCallDebugPrepareStepIn(argc), Code);
 }
 
 
 BreakLocationIterator::BreakLocationIterator(Handle<DebugInfo> debug_info,
                                              BreakLocatorType type) {
   debug_info_ = debug_info;
   type_ = type;
-  // Get the stub early to avoid possible GC during iterations. We may need
-  // this stub to detect debugger calls generated from debugger statements.
-  debug_break_stub_ = RuntimeStub(Runtime::kDebugBreak, 0).GetCode();
   reloc_iterator_ = NULL;
   reloc_iterator_original_ = NULL;
   Reset();  // Initialize the rest of the member variables.
 }
 
 
 BreakLocationIterator::~BreakLocationIterator() {
   ASSERT(reloc_iterator_ != NULL);
   ASSERT(reloc_iterator_original_ != NULL);
   delete reloc_iterator_;
@@ skipping 363 matching lines @@
   }
 }
 
 
 bool BreakLocationIterator::IsDebuggerStatement() {
   if (RelocInfo::IsCodeTarget(rmode())) {
     Address target = original_rinfo()->target_address();
     Code* code = Code::GetCodeFromTargetAddress(target);
     if (code->kind() == Code::STUB) {
       CodeStub::Major major_key = code->major_key();
-      if (major_key == CodeStub::Runtime) {
-        return (*debug_break_stub_ == code);
-      }
+      return (major_key == CodeStub::DebuggerStatement);
     }
   }
   return false;
 }
 
 
 Object* BreakLocationIterator::BreakPointObjects() {
   return debug_info_->GetBreakPointObjects(code_position());
 }
 
@@ skipping 2322 matching lines @@
     {
       Locker locker;
       Debugger::CallMessageDispatchHandler();
     }
   }
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal