[Bug libstdc++/70101] Allocator-extended priority_queue constructors are badly broken

[rs2740 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70101

--- Comment #1 from TC <rs2740 at gmail dot com> ---
Test case for everything except the first:

#include <queue>
#include <functional>
#include <vector>
#include <memory>
#include <utility>

struct Cmp : std::less<int> {
    explicit Cmp(int) {};
};

Cmp comp(1);
std::allocator<int> alloc;
std::vector<int> vec;

using PQ = std::priority_queue<int, std::vector<int>, Cmp>;

PQ pq2(comp, alloc);
PQ pq3(comp, vec, alloc);
PQ pq4(comp, std::move(vec), alloc);
PQ pq5(pq2, alloc);
PQ pq6(std::move(pq2), alloc);