[ADT] Change iterator_adaptor_base's default template arguments to forward more underlying typedefs
Summary:
The corresponding LLVM change: D23217.
LazyVector::iterator breaks, because int isn't an iterator type.
Since iterator_adaptor_base shouldn't be blamed to break at the call to
iterator_traits<int>::xxx, I'd rather "fix" LazyVector::iterator.
The perfect solution is to model "relative pointer", but it's beyond the goal of this patch.
Reviewers: chandlerc, bkramer
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D23218
llvm-svn: 278156