Summary:
This sometimes fail in our CI, eg:
```
[*ERROR**][66148] file has vanished: "/data/sandcastle/boxes/trunk-git-infer/infer/tests/build_systems/utf8_in_pwd/../codetoanalyze/make/utf8_in_function_names-617be4bc.o.tmp"
```
The issue seems to be that we are too greedy and try and copy files that may
disappear. This diff makes the list of files to copy over explicit to exclude
such temporary files.
Reviewed By: artempyanykh
Differential Revision: D16261872
fbshipit-source-id: 2b080d27a