New __ptrauth scalar types are wrongly reported as trivially copy/move constructible

Follows #137473 and #154394.
https://godbolt.org/z/zhsdnxKPe
```
using PA = void * __ptrauth(0,1,0);
template struct H { T t; };

static_assert(!__is_trivially_copyable(PA));
static_assert(__is_trivially_constructible(PA, PA&)); // WRONG
static_assert(__is_trivially_assignable(PA&, PA&)); // WRONG
static_assert(!__is_trivially_copyable(H));
static_assert(!__is_trivially_constructible(H, H&));
static_assert(!__is_trivially_assignable(H&, H&));
```
It cannot be that `PA` is trivially constructible and assignable by itself alone, but becomes non-trivial only when placed into a class type `H`. It also cannot be that `PA` is trivially constructible, assignable, and destructible, yet is not trivially_copyable. The conclusion is that `PA` must be non-trivial even when it is alone.

@ojhunt will you look please?

Start with the Compiler Explorer reproducer linked in the issue and inspect how the new __ptrauth scalar type is classified by the trivial construction and assignment traits. The fix is complete when the listed static assertions pass consistently for PA and H.

Written by the indexing model from the issue text.