[libcxx] Apply _LIBCPP_INLINE_VISIBILITY for std::hash for string_view

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@347765 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/string_view b/include/string_view
index 55dce72..dd425a2 100644
--- a/include/string_view
+++ b/include/string_view
@@ -778,17 +778,12 @@
 struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, _Traits> >
     : public unary_function<basic_string_view<_CharT, _Traits>, size_t>
 {
-    size_t operator()(const basic_string_view<_CharT, _Traits> __val) const _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(const basic_string_view<_CharT, _Traits> __val) const _NOEXCEPT {
+        return __do_string_hash(__val.data(), __val.data() + __val.size());
+    }
 };
 
-template<class _CharT, class _Traits>
-size_t
-hash<basic_string_view<_CharT, _Traits> >::operator()(
-        const basic_string_view<_CharT, _Traits> __val) const _NOEXCEPT
-{
-    return __do_string_hash(__val.data(), __val.data() + __val.size());
-}
-
 
 #if _LIBCPP_STD_VER > 11 
 inline namespace literals