Patch to enhance the source code line information for profiler.

src/x64/lithium-x64.cc

 // Copyright 2012 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 882 matching lines @@
         if (LUnallocated::cast(instr->Output())->HasFixedPolicy()) ++fixed;
       }
       for (TempIterator it(instr); !it.Done(); it.Advance()) {
         LUnallocated* operand = LUnallocated::cast(it.Current());
         if (operand->HasFixedPolicy()) ++fixed;
       }
       ASSERT(fixed == 0 || used_at_start == 0);
     }
 #endif
 
+    instr->set_position(position_);
+
     if (FLAG_stress_pointer_maps && !instr->HasPointerMap()) {
       instr = AssignPointerMap(instr);
     }
     if (FLAG_stress_environments && !instr->HasEnvironment()) {
       instr = AssignEnvironment(instr);
     }
     instr->set_hydrogen_value(current);
     chunk_->AddInstruction(instr, current_block_);
   }
   current_instruction_ = old_current;
@@ skipping 1641 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64