Strict mode delete.

src/x64/full-codegen-x64.cc

 // 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 3052 matching lines @@
         // The subexpression does not have side effects.
         context()->Plug(false);
       } else if (prop != NULL) {
         if (prop->is_synthetic()) {
           // Result of deleting parameters is false, even when they rewrite
           // to accesses on the arguments object.
           context()->Plug(false);
         } else {
           VisitForStackValue(prop->obj());
           VisitForStackValue(prop->key());
+          __ Push(Smi::FromInt(strict_mode_flag()));
           __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
           context()->Plug(rax);
         }
       } else if (var->is_global()) {
+        ASSERT(strict_mode_flag() == kNonStrictMode);
         __ push(GlobalObjectOperand());
         __ Push(var->name());
+        __ Push(Smi::FromInt(kNonStrictMode));
         __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
         context()->Plug(rax);
       } else {
         // Non-global variable.  Call the runtime to try to delete from the
         // context where the variable was introduced.
         __ push(context_register());
         __ Push(var->name());
         __ CallRuntime(Runtime::kDeleteContextSlot, 2);
         context()->Plug(rax);
       }
@@ skipping 657 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64