A64: Tidy up a few TODOs.

src/a64/macro-assembler-a64.cc

 // Copyright 2013 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 1740 matching lines @@
                                         Builtins::JavaScript id) {
   // Load the builtins object into target register.
   Ldr(target, GlobalObjectMemOperand());
   Ldr(target, FieldMemOperand(target, GlobalObject::kBuiltinsOffset));
   // Load the JavaScript builtin function from the builtins object.
   Ldr(target, FieldMemOperand(target,
                           JSBuiltinsObject::OffsetOfFunctionWithId(id)));
 }
 
 
-void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
-  ASSERT(!target.is(x1));
-  GetBuiltinFunction(x1, id);
+void MacroAssembler::GetBuiltinEntry(Register target,
+                                     Register function,
+                                     Builtins::JavaScript id) {
+  ASSERT(!AreAliased(target, function));
+  GetBuiltinFunction(function, id);
   // Load the code entry point from the builtins object.
-  Ldr(target, FieldMemOperand(x1, JSFunction::kCodeEntryOffset));
+  Ldr(target, FieldMemOperand(function, JSFunction::kCodeEntryOffset));
 }
 
 
 void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
                                    InvokeFlag flag,
                                    const CallWrapper& call_wrapper) {
   ASM_LOCATION("MacroAssembler::InvokeBuiltin");
   // You can't call a builtin without a valid frame.
   ASSERT(flag == JUMP_FUNCTION || has_frame());
 
-  GetBuiltinEntry(x2, id);
+  // Get the builtin entry in x2 and setup the function object in x1.
+  GetBuiltinEntry(x2, x1, id);
   if (flag == CALL_FUNCTION) {
     call_wrapper.BeforeCall(CallSize(x2));
     Call(x2);
     call_wrapper.AfterCall();
   } else {
     ASSERT(flag == JUMP_FUNCTION);
     Jump(x2);
   }
 }
 
@@ skipping 3318 matching lines @@
   }
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_A64