PR libstdc++/69293
	* include/bits/uses_allocator.h (__uses_alloc<true, ...>): Add
	static assertion that type is constructible from the arguments.
	* testsuite/20_util/scoped_allocator/69293_neg.cc: New.
	* testsuite/20_util/uses_allocator/69293_neg.cc: New.
	* testsuite/20_util/uses_allocator/cons_neg.cc: Adjust dg-error.

From-SVN: r232457