A64: Tidy up a few TODOs.

src/a64/macro-assembler-a64.h

 // 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 1029 matching lines @@
   void CallRuntime(const Runtime::Function* f,
                    int num_arguments,
                    SaveFPRegsMode save_doubles = kDontSaveFPRegs);
 
   void CallRuntime(Runtime::FunctionId id,
                    int num_arguments,
                    SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
     CallRuntime(Runtime::FunctionForId(id), num_arguments, save_doubles);
   }
 
-  // TODO(all): Why does this variant save FP regs unconditionally?
   void CallRuntimeSaveDoubles(Runtime::FunctionId id) {
     const Runtime::Function* function = Runtime::FunctionForId(id);
     CallRuntime(function, function->nargs, kSaveFPRegs);
   }
 
   void TailCallRuntime(Runtime::FunctionId fid,
                        int num_arguments,
                        int result_size);
 
   int ActivationFrameAlignment();
@@ skipping 42 matching lines @@
                              int num_arguments);
 
 
   // Invoke specified builtin JavaScript function. Adds an entry to
   // the unresolved list if the name does not resolve.
   void InvokeBuiltin(Builtins::JavaScript id,
                      InvokeFlag flag,
                      const CallWrapper& call_wrapper = NullCallWrapper());
 
   // Store the code object for the given builtin in the target register and
-  // setup the function in x1.
-  // TODO(all): Can we use another register than x1?
-  void GetBuiltinEntry(Register target, Builtins::JavaScript id);
+  // setup the function in the function register.
+  void GetBuiltinEntry(Register target,
+                       Register function,
+                       Builtins::JavaScript id);
 
   // Store the function for the given builtin in the target register.
   void GetBuiltinFunction(Register target, Builtins::JavaScript id);
 
   void Jump(Register target);
   void Jump(Address target, RelocInfo::Mode rmode);
   void Jump(Handle<Code> code, RelocInfo::Mode rmode);
   void Jump(intptr_t target, RelocInfo::Mode rmode);
 
   void Call(Register target);
@@ skipping 1148 matching lines @@
 #error "Unsupported option"
 #define CODE_COVERAGE_STRINGIFY(x) #x
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 #endif  // V8_A64_MACRO_ASSEMBLER_A64_H_