Prior to C++20 it should be ill-formed to use std::make_shared with an
array type (and we don't support the C++20 feature to make it valid yet
anyway).
libstdc++-v3/ChangeLog:
PR libstdc++/99006
* include/bits/shared_ptr.h (allocate_shared): Assert that _Tp
is not an array type.
* include/bits/shared_ptr_base.h (__allocate_shared): Likewise.
* testsuite/20_util/shared_ptr/creation/99006.cc: New test.
55650236cd