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

src/builtins-arm.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) {
-  // r0 contains the number of arguments excluding the receiver.
-  // JumpToBuiltin expects r0 to contains the number of arguments
-  // including the receiver.
-  __ mov(r0, Operand(argc + 1));
+  // TODO(1238487): Don't pass the function in a static variable.
   __ mov(ip, Operand(ExternalReference::builtin_passed_function()));
   __ str(r1, MemOperand(ip, 0));
+
+  if (argc == -1) {
+    // The actual argument count has already been loaded into register
+    // r0, but JumpToBuiltin expects r0 to contain the number of
+    // arguments including the receiver.
+    __ add(r0, r0, Operand(1));
+  } else {
+    // The number passed in argc excludes the receiver, but
+    // JumpToBuiltin expects r0 to contain the number of arguments
+    // including the receiver.
+    __ mov(r0, Operand(argc + 1));
+  }
   __ JumpToBuiltin(ExternalReference(id));
 }
 
 
 void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r0     : number of arguments
   //  -- r1     : constructor function
   //  -- lr     : return address
   //  -- sp[...]: constructor arguments
@@ skipping 769 matching lines @@
 }
 
 void Builtins::Generate_StubNoRegisters_DebugBreak(MacroAssembler* masm) {
   // Generate nothing as CodeStub CallFunction is not used on ARM.
 }
 
 
 #undef __
 
 } }  // namespace v8::internal