Patch to enhance the source code line information for profiler.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 255 matching lines @@
     }
     if (!emit_instructions) continue;
 
     if (FLAG_code_comments && instr->HasInterestingComment(this)) {
       Comment(";;; <@%d,#%d> %s",
               current_instruction_,
               instr->hydrogen_value()->id(),
               instr->Mnemonic());
     }
 
+    int pos = instr->position();
+    if (pos >= 0) RecordPosition(pos);
+
     instr->CompileToNative(this);
   }
   EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
   return !is_aborted();
 }
 
 
 bool LCodeGen::GenerateJumpTable() {
   Label needs_frame;
   if (jump_table_.length() > 0) {
@@ skipping 5251 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64