Remove comment discussing non-existent ARRAYSIZE_UNSAFE macro

src/base/macros.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_BASE_MACROS_H_
 #define V8_BASE_MACROS_H_
 
 #include "src/base/compiler-specific.h"
 #include "src/base/format-macros.h"
 #include "src/base/logging.h"
 
 
 // TODO(all) Replace all uses of this macro with C++'s offsetof. To do that, we
 // have to make sure that only standard-layout types and simple field
 // designators are used.
 #define OFFSET_OF(type, field) \
   (reinterpret_cast<intptr_t>(&(reinterpret_cast<type*>(16)->field)) - 16)
 
 
 // The arraysize(arr) macro returns the # of elements in an array arr.
 // The expression is a compile-time constant, and therefore can be
 // used in defining new arrays, for example.  If you use arraysize on
 // a pointer by mistake, you will get a compile-time error.
-//
-// One caveat is that arraysize() doesn't accept any array of an
-// anonymous type or a type defined inside a function.  In these rare
-// cases, you have to use the unsafe ARRAYSIZE_UNSAFE() macro below.  This is
-// due to a limitation in C++'s template system.  The limitation might
-// eventually be removed, but it hasn't happened yet.
 #define arraysize(array) (sizeof(ArraySizeHelper(array)))
 
 
 // This template function declaration is used in defining arraysize.
 // Note that the function doesn't need an implementation, as we only
 // use its type.
 template <typename T, size_t N>
 char (&ArraySizeHelper(T (&array)[N]))[N];
 
 
@@ skipping 261 matching lines @@
 
 template <>
 inline bool is_fundamental<uint8_t>() {
   return true;
 }
 
 }  // namespace base
 }  // namespace v8
 
 #endif   // V8_BASE_MACROS_H_