libstdc++: Add workaround to std::ranges::subrange [PR111948]

libstdc++-v3/ChangeLog:

	PR libstdc++/111948
	* include/bits/ranges_util.h (subrange): Add constructor to
	_Size to avoid setting member in constructor.
	* testsuite/std/ranges/subrange/111948.cc: New test.

(cherry picked from commit 08448dc1)