Update the release notes about the min/max reductions that Arnold added.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180805 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a typo

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180806 91177308-0d34-0410-b5e6-96231b3b80d8