insertelement/extractelement.
I'm not entirely sure this is precisely what we want to do: should we
prefer bitcast(insertelement) or insertelement(bitcast)? Similarly. should we
prefer extractelement(bitcast) or bitcast(extractelement)?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76345 91177308-0d34-0410-b5e6-96231b3b80d8