Don't use eax on x64. :)

TBR=ricow

Review URL: http://codereview.chromium.org/6312122

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6624 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/x64/lithium-codegen-x64.cc

@@ -1529,7 +1529,7 @@ void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
     __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
   }
 
-  // Set eax to arguments count if adaption is not needed. Assumes that eax
+  // Set rax to arguments count if adaption is not needed. Assumes that rax
   // is available to write to at this point.
   if (!function->NeedsArgumentsAdaption()) {
     __ Set(rax, arity);
@@ -1554,7 +1554,7 @@ void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
 
 
 void LCodeGen::DoCallConstantFunction(LCallConstantFunction* instr) {
-  ASSERT(ToRegister(instr->result()).is(eax));
+  ASSERT(ToRegister(instr->result()).is(rax));
   __ Move(rdi, instr->function());
   CallKnownFunction(instr->function(), instr->arity(), instr);
 }