Revert D23811085: gtestify dce and fuser tests
Test Plan: revert-hammer
Differential Revision:
D23811085 (https://github.com/pytorch/pytorch/commit/246bd9422a1f64965ad9082798c8b17f96bc2924)
Original commit changeset: 45008e41f239
fbshipit-source-id: 94c981f565cab9b710fe52a55bbe8dbf9c179c23
