Changes

Fix non-portable GNU diff option
Summary: This is a fix to revision D68839 and rL375023. This patch
substitutes POSIX option "-b" for the non-portable GNU option
"--strip-trailing-cr".
Reviewers: daltenty, hubert.reinterpretcast
Reviewed By: daltenty
Subscribers: mehdi_amini, hiraditya, steven_wu, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69342