Delete SymIntArrayRef wrapper struct (#84837)
Since we separated at::foo and at::foo_symint there is no benefit
to trying to make initializer lists work in both cases. So we can
get rid of the special different struct.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/84837
Approved by: https://github.com/kit1980
