[ADT] Pass DerivedT from pointe{e,r}_iterator to iterator_adaptor_base

These were passing the wrong type into iterator_adaptor_base if T was
anything but the default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335698 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed