Squashed 'third_party/boostorg/iterator/' content from commit b2adecb

Change-Id: I284a73816f9cc846742923879275b84c6e0c915c
git-subtree-dir: third_party/boostorg/iterator
git-subtree-split: b2adecb951af025698618f19a3c838bd314966dc
257 files changed