[builtins] Some refactoring on the builtin mechanism.

src/x64/builtins-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/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
 
 namespace v8 {
 namespace internal {
 
 
 #define __ ACCESS_MASM(masm)
 
 
 void Builtins::Generate_Adaptor(MacroAssembler* masm,
                                 CFunctionId id,
                                 BuiltinExtraArguments extra_args) {
   // ----------- S t a t e -------------
   //  -- rax                 : number of arguments excluding receiver
-  //  -- rdi                 : called function
+  //  -- rdi                 : target
+  //  -- rdx                 : new.target
   //  -- rsp[0]              : return address
   //  -- rsp[8]              : last argument
   //  -- ...
   //  -- rsp[8 * argc]       : first argument
   //  -- rsp[8 * (argc + 1)] : receiver
   // -----------------------------------
   __ AssertFunction(rdi);
 
   // Insert extra arguments.
   int num_extra_args = 0;
-  if (extra_args == NEEDS_CALLED_FUNCTION) {
-    num_extra_args = 1;
+  if (extra_args != BuiltinExtraArguments::kNone) {
     __ PopReturnAddressTo(kScratchRegister);
-    __ Push(rdi);
+    if (extra_args & BuiltinExtraArguments::kTarget) {
+      ++num_extra_args;
+      __ Push(rdi);
+    }
+    if (extra_args & BuiltinExtraArguments::kNewTarget) {
+      ++num_extra_args;
+      __ Push(rdx);
+    }
     __ PushReturnAddressFrom(kScratchRegister);
-  } else {
-    DCHECK(extra_args == NO_EXTRA_ARGUMENTS);
   }
 
   // JumpToExternalReference expects rax to contain the number of arguments
   // including the receiver and the extra arguments.
   __ addp(rax, Immediate(num_extra_args + 1));
 
   __ JumpToExternalReference(ExternalReference(id, masm->isolate()), 1);
 }
 
 
@@ skipping 1988 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64