Unfortunately I don't think there's a fix for this that will work upstream and
also satisfy Clang's -Wunreachable-code, which is a pity. But I'll give it some
more thought -perhaps there's some way out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148645 91177308-0d34-0410-b5e6-96231b3b80d8