Filter default tests for `clang` coverage in oss
Summary: Some tests like `test_dataloader.py` are not able to run under `clang` in oss, because it generates too large intermediate files (~40G) that can't be merged by `llvm`. Skip them when user doesn't specify the `--run-only` option
Test Plan: Test locally. But still, not recomend user to run `clang` coverage in default mode, because it takes too much space.
Reviewed By: malfet
Differential Revision: D23549829
fbshipit-source-id: 0737e6e9dcbe3f38de00580ee6007906e743e52f
