Alternatively, this type could be derived on-demand whenever
getResultElementType is called - if someone thinks that's the better
choice (simple time/space tradeoff), I'm happy to give it a go.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238716 91177308-0d34-0410-b5e6-96231b3b80d8