[llvm] [gitattributes] Mark some llvm-rc inputs as requiring LF newlines (PR #113222)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

Thanks!

FWIW, the same approach should also work as a remedy for the issues on AIX, where `diff --strip-trailing-cr` wasn't supported, to avoid needing to change the shell execution method (which could end up as a longer chain of changes).

https://github.com/llvm/llvm-project/pull/113222