graph mode: round out relu support (#37592)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37592
Makes sure that all the standalone relu flavors are tested in
graph mode.
Test Plan:
```
python test/test_quantization.py TestQuantizeScriptPTSQOps.test_swap_dequantize
```
Imported from OSS
Differential Revision: D21366597
fbshipit-source-id: 103848b76a0c65b9adac5bae98b545aa1d30a9e2
