Less confusing way of denoting dimension in symint name (#82317)
s_0^0 can be misinterpreted as s_0 exponentiated to 0;
s_0[0] is fairly unambiguously array access.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/82317
Approved by: https://github.com/Chillee
