ptrtoint and inttoptr in X86FastISel. These casts aren't always
handled in the generic FastISel code because X86 sometimes needs
custom code to do truncation and zero-extension.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66988 91177308-0d34-0410-b5e6-96231b3b80d8