[runtime] Remove useless DELETE builtin.

src/full-codegen/x64/full-codegen-x64.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/compiler.h"
@@ skipping 4548 matching lines @@
 void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
   switch (expr->op()) {
     case Token::DELETE: {
       Comment cmnt(masm_, "[ UnaryOperation (DELETE)");
       Property* property = expr->expression()->AsProperty();
       VariableProxy* proxy = expr->expression()->AsVariableProxy();
 
       if (property != NULL) {
         VisitForStackValue(property->obj());
         VisitForStackValue(property->key());
-        __ Push(Smi::FromInt(language_mode()));
-        __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
+        __ CallRuntime(is_strict(language_mode())
+                           ? Runtime::kDeleteProperty_Strict
+                           : Runtime::kDeleteProperty_Sloppy,
+                       2);
         context()->Plug(rax);
       } else if (proxy != NULL) {
         Variable* var = proxy->var();
         // Delete of an unqualified identifier is disallowed in strict mode but
         // "delete this" is allowed.
         bool is_this = var->HasThisName(isolate());
         DCHECK(is_sloppy(language_mode()) || is_this);
         if (var->IsUnallocatedOrGlobalSlot()) {
           __ Push(GlobalObjectOperand());
           __ Push(var->name());
-          __ Push(Smi::FromInt(SLOPPY));
-          __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
+          __ CallRuntime(Runtime::kDeleteProperty_Sloppy, 2);
           context()->Plug(rax);
         } else if (var->IsStackAllocated() || var->IsContextSlot()) {
           // Result of deleting non-global variables is false.  'this' is
           // not really a variable, though we implement it as one.  The
           // subexpression does not have side effects.
           context()->Plug(is_this);
         } else {
           // Non-global variable.  Call the runtime to try to delete from the
           // context where the variable was introduced.
           __ Push(context_register());
@@ skipping 707 matching lines @@
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64