Add a release not about llvm-ar.

Thanks to Bill Wendling for the reminder.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187794 91177308-0d34-0410-b5e6-96231b3b80d8
ARM: implement allowTruncateForTailCall

Now that it's in place, it seems silly not to let ARM make use of the extra
tail call opportunities.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187795 91177308-0d34-0410-b5e6-96231b3b80d8