[git-llvm] Make `push` work on CRLF files with svn:eol-style=native

Summary:
`git apply` on Windows doesn't work for files that SVN checks out as
CRLF. There is no way to force SVN to check everything out with Unix
line endings on Windows. Files with svn:eol-style=native will always
come out with CRLF, breaking `git apply`, which wants Unix line endings.
My workaround is to list all files with this property set in the change,
and run `dos2unix` on them. SVN doesn't commit a massive line ending
change because the svn:eol-style property indicates that these are text
files.

Tested on r301245.

Reviewers: zturner, jlebar

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32452

llvm-svn: 301262