ADT: Remove ilist_iterator random access API, NFC

Remove explicitly deleted random access API from ilist_iterator.
Since it no longer has implicit conversions to a pointer type, we
no longer need this protection.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261491 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed