First take on custom call generators.

src/ia32/codegen-ia32.cc

 // Copyright 2010 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 10199 matching lines @@
   // Generate code to lookup number in the number string cache.
   GenerateLookupNumberStringCache(masm, ebx, eax, ecx, edx, false, &runtime);
   __ ret(1 * kPointerSize);
 
   __ bind(&runtime);
   // Handle number to string in the runtime system if not found in the cache.
   __ TailCallRuntime(Runtime::kNumberToString, 1, 1);
 }
 
 
+void RecordWriteStub::Generate(MacroAssembler* masm) {
+  masm->RecordWriteHelper(object_, addr_, scratch_);
+  masm->ret(0);
+}
+
+
 void CompareStub::Generate(MacroAssembler* masm) {
   Label call_builtin, done;
 
   // NOTICE! This code is only reached after a smi-fast-case check, so
   // it is certain that at least one operand isn't a smi.
 
   if (cc_ == equal) {  // Both strict and non-strict.
     Label slow;  // Fallthrough label.
     // Equality is almost reflexive (everything but NaN), so start by testing
     // for "identity and not NaN".
@@ skipping 1578 matching lines @@
 
   // Call the runtime; it returns -1 (less), 0 (equal), or 1 (greater)
   // tagged as a small integer.
   __ bind(&runtime);
   __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
 }
 
 #undef __
 
 } }  // namespace v8::internal