Add _LIBCPP_HIDE_FROM_ABI.

Author: xingxue-ibm

libcxx/include/ios

@@ -526,10 +526,10 @@ template <class _Traits>
 // Attribute 'packed' is used to keep the layout compatible with the previous
 // definition of the '__fill_' and '_set_' pair in basic_ios on AIX & z/OS.
 struct _LIBCPP_PACKED _OptionalFill {
-  _OptionalFill() : __set_(false) { }
-  _OptionalFill& operator=(typename _Traits::int_type __x) { __set_ = true; __fill_val_ = __x; return *this; }
-  bool __is_set() const { return __set_; }
-  typename _Traits::int_type __fill() const { return __fill_val_; }
+  _LIBCPP_HIDE_FROM_ABI _OptionalFill() : __set_(false) { }
+  _LIBCPP_HIDE_FROM_ABI _OptionalFill& operator=(typename _Traits::int_type __x) { __set_ = true; __fill_val_ = __x; return *this; }
+  _LIBCPP_HIDE_FROM_ABI bool __is_set() const { return __set_; }
+  _LIBCPP_HIDE_FROM_ABI typename _Traits::int_type __fill() const { return __fill_val_; }
 
 private:
   typename _Traits::int_type __fill_val_;
@@ -538,10 +538,10 @@ private:
 
 template <class _Traits>
 struct _LIBCPP_PACKED _SentinelValueFill {
-  _SentinelValueFill() : __fill_val_(_Traits::eof()) { }
-  _SentinelValueFill& operator=(typename _Traits::int_type __x) { __fill_val_ = __x; return *this; }
-  bool __is_set() const { return __fill_val_ != _Traits::eof(); }
-  typename _Traits::int_type __fill() const { return __fill_val_; }
+  _LIBCPP_HIDE_FROM_ABI _SentinelValueFill() : __fill_val_(_Traits::eof()) { }
+  _LIBCPP_HIDE_FROM_ABI _SentinelValueFill& operator=(typename _Traits::int_type __x) { __fill_val_ = __x; return *this; }
+  _LIBCPP_HIDE_FROM_ABI bool __is_set() const { return __fill_val_ != _Traits::eof(); }
+  _LIBCPP_HIDE_FROM_ABI typename _Traits::int_type __fill() const { return __fill_val_; }
 
 private:
   typename _Traits::int_type __fill_val_;