Revert r346810 "Preserve loop metadata when splitting exit blocks"

It broke the Windows self-host:
http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/1457

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346823 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed