[libcxx] Remove inline/visibility attributes from exported template methods in valarray.

[eugenis]

Summary

This does not affect the libc++ export list now.
It is required for internal_linkage switch to not affect the libc++ export list.
This patch is on top of D15432.

[EricWF]

Won't this mean that libc++ possibly exports 3 more template definitions? I think this is likely safe but I would rather not export any more symbols if it can be avoided.

I'm probably nitpicking here though.

include/valarray

823

So I think we still want the almost every instantiation of valarray<Tp>::~valarray() to have internal linkage except for the specialization valarray<size_t>::~valarray(); Do you see any way to make this possible?

[eugenis]

Libc++.so does not instantiate valarray for any other types, so this does not add any extra exports.

Definitions valarray members (with types other than size_t) will now be exported from user code. This looks like a positive change to me:

• these methods are already part of the ABI due to the exported template valarray<size_t>
• exported vs hidden/internal can produce smaller code

include/valarray

 private:
     value_type* __begin_;
     value_type* __end_;
 
 public:
     // construct/destroy:
     _LIBCPP_INLINE_VISIBILITY
     valarray() : __begin_(0), __end_(0) {}
-    _LIBCPP_INLINE_VISIBILITY
     explicit valarray(size_t __n);
     _LIBCPP_INLINE_VISIBILITY
     valarray(const value_type& __x, size_t __n);
     valarray(const value_type* __p, size_t __n);
     valarray(const valarray& __v);
 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
     _LIBCPP_INLINE_VISIBILITY
     valarray(valarray&& __v) _NOEXCEPT;
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 #ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
     valarray(initializer_list<value_type> __il);
 #endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
     valarray(const slice_array<value_type>& __sa);
     valarray(const gslice_array<value_type>& __ga);
     valarray(const mask_array<value_type>& __ma);
     valarray(const indirect_array<value_type>& __ia);
 
-    _LIBCPP_INLINE_VISIBILITY
     ~valarray();
 
     // assignment:
     valarray& operator=(const valarray& __v);
 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
     _LIBCPP_INLINE_VISIBILITY
     valarray& operator=(valarray&& __v) _NOEXCEPT;
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
#ifndef _LIBCPP_NO_EXCEPTIONS
             throw;
         }
 #endif  // _LIBCPP_NO_EXCEPTIONS
     }
 }
 
 
 template <class _Tp>
-inline
 valarray<_Tp>::valarray(size_t __n)
     : __begin_(0),
       __end_(0)
 {
     resize(__n);
 }
 
 template <class _Tp>
-inline
 valarray<_Tp>::~valarray()
 {
     resize(0);
 }
 
 // The definition for these three functions must appear before they are used and
 // before these extern template declarations.
 // Otherwise GCC will fail to inline the definition which is an error because