Breakpoint position should be inside function body.

src/x64/full-codegen-x64.cc

 // Copyright 2010 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 189 matching lines @@
     __ bind(&return_label_);
     if (FLAG_trace) {
       __ push(rax);
       __ CallRuntime(Runtime::kTraceExit, 1);
     }
 #ifdef DEBUG
     // Add a label for checking the size of the code used for returning.
     Label check_exit_codesize;
     masm_->bind(&check_exit_codesize);
 #endif
-    CodeGenerator::RecordPositions(masm_, function()->end_position());
+    CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
     __ RecordJSReturn();
     // Do not use the leave instruction here because it is too short to
     // patch with the code required by the debugger.
     __ movq(rsp, rbp);
     __ pop(rbp);
     __ ret((scope()->num_parameters() + 1) * kPointerSize);
 #ifdef ENABLE_DEBUGGER_SUPPORT
     // Add padding that will be overwritten by a debugger breakpoint.  We
     // have just generated "movq rsp, rbp; pop rbp; ret k" with length 7
     // (3 + 1 + 3).
@@ skipping 3040 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64