Stop adapting the arguments passed to the builtin implementations...

src/builtins-ia32.cc

 // Copyright 2006-2008 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 22 matching lines @@
 
 namespace v8 { namespace internal {
 
 
 #define __ masm->
 
 
 void Builtins::Generate_Adaptor(MacroAssembler* masm,
                                 int argc,
                                 CFunctionId id) {
-  // argc is the number of arguments excluding the receiver.
-  // JumpToBuiltin expects eax to contain the number of arguments
-  // including the receiver.
-  __ mov(eax, argc + 1);
-  __ mov(Operand::StaticVariable(ExternalReference::builtin_passed_function()),
-         edi);
+  // TODO(1238487): Don't pass the function in a static variable.
+  ExternalReference passed = ExternalReference::builtin_passed_function();
+  __ mov(Operand::StaticVariable(passed), edi);
+
+  if (argc == -1) {
+    // The actual argument count has already been loaded into register
+    // eax, but JumpToBuiltin expects eax to contain the number of
+    // arguments including the receiver.
+    __ inc(eax);
+  } else {
+    // The number passed in argc excludes the receiver, but
+    // JumpToBuiltin expects eax to contain the number of arguments
+    // including the receiver.
+    __ mov(eax, argc + 1);
+  }
   __ JumpToBuiltin(ExternalReference(id));
 }
 
 
 void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax: number of arguments
   //  -- edi: constructor function
   // -----------------------------------
 
@@ skipping 817 matching lines @@
   // Register state for stub CallFunction (from CallFunctionStub in ic-ia32.cc).
   // ----------- S t a t e -------------
   //  No registers used on entry.
   // -----------------------------------
   Generate_DebugBreakCallHelper(masm, 0, false);
 }
 
 #undef __
 
 } }  // namespace v8::internal