libstdc++: Fix invalid noexcept-specifier (PR 94117)

G++ fails to diagnose this non-dependent expression, but Clang doesn't
like it.

	PR c++/94117
	* include/std/ranges (ranges::transform_view::_Iterator::iter_move):
	Change expression in noexcept-specifier to match function body.

libstdc++-v3/ChangeLog

 2020-03-10  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR c++/94117
+	* include/std/ranges (ranges::transform_view::_Iterator::iter_move):
+	Change expression in noexcept-specifier to match function body.
+
 	* testsuite/23_containers/unordered_set/allocator/ext_ptr.cc: Add
 	comment explaining multiple dg-do directives.
 	* testsuite/24_iterators/ostream_iterator/1.cc: Fix do-do directive

libstdc++-v3/include/std/ranges

@@ -1837,7 +1837,7 @@ namespace views
 	  { return __x._M_current - __y._M_current; }
 
 	  friend constexpr decltype(auto)
-	  iter_move(const _Iterator& __i) noexcept(noexcept(__iter_move()))
+	  iter_move(const _Iterator& __i) noexcept(noexcept(__iter_move(__i)))
 	  { return __iter_move(__i); }
 
 	  friend constexpr void