Vector is not trivially copyable

[krzikalla]

If you change

Vc/Vc/common/simdarrayfwd.h

Lines 49 to 54 in b84dcd0

	Vc_INTRINSIC Vector(const Vector &x) : SimdArray<T, N>(x) {}
	Vc_INTRINSIC Vector &operator=(const Vector &x)
	{
	SimdArray<T, N>::operator=(x);
	return *this;
	}

to

    Vc_INTRINSIC Vector(const Vector &x) = default;
    Vc_INTRINSIC Vector &operator=(const Vector &x) = default;

Vector and in turn SimdArray becomes trivially copyable. Currently we get a lot of warnings with gcc 11.2, if we use Vc types together with memcpy (which we can't change).
I don't see any problems resulting in the proposed change.