[runtime] Remove useless DELETE builtin.

src/compiler/js-generic-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-generic-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 412 matching lines @@
       node->RemoveInput(3);
     }
     ReplaceWithStubCall(node, callable,
                         CallDescriptor::kPatchableCallSite | flags);
   }
 }
 
 
 void JSGenericLowering::LowerJSDeleteProperty(Node* node) {
   LanguageMode language_mode = OpParameter<LanguageMode>(node);
-  ReplaceWithBuiltinCall(node, Builtins::DELETE, 3);
-  node->InsertInput(zone(), 4, jsgraph()->SmiConstant(language_mode));
+  ReplaceWithRuntimeCall(node, is_strict(language_mode)
+                                   ? Runtime::kDeleteProperty_Strict
+                                   : Runtime::kDeleteProperty_Sloppy);
 }
 
 
 void JSGenericLowering::LowerJSHasProperty(Node* node) {
   ReplaceWithBuiltinCall(node, Builtins::IN, 2);
 }
 
 
 void JSGenericLowering::LowerJSInstanceOf(Node* node) {
   CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
@@ skipping 403 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8