Port `sum.dim_IntList` kernel to structured kernels. (#61642)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61642
Tracking issue: #55070
Test Plan: Imported from OSS
Reviewed By: ejguan
Differential Revision: D29783865
Pulled By: ezyang
fbshipit-source-id: 375d4cd5f915812108367601a610a428762e606d
