Revert D25277886: [pytorch][PR] Replace constexpr with CONSTEXPR_EXCEPT_WIN_CUDA
Test Plan: revert-hammer
Differential Revision:
D25277886 (https://github.com/pytorch/pytorch/commit/0484b048d050ea5b10cb0efd147148aa893f2a4b)
Original commit changeset: eb845db35d31
fbshipit-source-id: 133b938ff8ae1aa54878a03ea5a7e732c6bd5901
