Stop benchmarking compile time of dead code (#145590)
Summary:
FIXES https://github.com/pytorch/pytorch/issues/144775 frfr
See details on the problem: https://github.com/pytorch/pytorch/issues/144775#issuecomment-2611699385
We fixed some silent incorrectness, but it results in less nodes DCE'd. The benchmark iteration loop had some dead code which could contain side effect ops that aren't safe to DCE. The regression is expected.
This PR removes the compile time benchmarking of the dead code, which should reduce the noise of the benchmark and aligns with the benchmarking used by performance tests
New benchmark results:
```python
dev,name,batch_size,accuracy,calls_captured,unique_graphs,graph_breaks,unique_graph_breaks,autograd_captures,autograd_compiles,cudagraph_skips,compilation_latency
cuda,BartForConditionalGeneration,1,pass,897,1,0,0,0,0,0,39.322364 # after https://github.com/pytorch/pytorch/pull/144319
cuda,BartForConditionalGeneration,1,pass,897,1,0,0,0,0,0,38.972257 # before https://github.com/pytorch/pytorch/pull/144319
```
X-link: https://github.com/pytorch/pytorch/pull/145590
Approved by: https://github.com/jansel
ghstack dependencies: #145447
Reviewed By: ZainRizvi
Differential Revision: D68860252
fbshipit-source-id: 60371bdf3ba6e6f38766d6589690a221f8cebda4
