[clang 3.6dev] fix warning due to new PredefinedExpr

Summary:
[clang 3.6dev] fix warning due to new PredefinedExpr

Add missing case in switch.

Test Plan: make test && make -C clang-ocaml test

Reviewers: ddino, dulmarod, irp

Reviewed By: irp

Subscribers: mathieubaudet

Differential Revision: https://phabricator.fb.com/D1558284

Tasks: 5134636
[clang 3.6dev] Modernize a few iterators

Summary:
[clang 3.6dev] Modernize a few iterators

I only did the obvious ones. This is more a reminder that we can (and should) use this new style when possible.

Test Plan: make test && make -C clang-ocaml test

Reviewers: ddino, dulmarod, irp

Reviewed By: irp

Subscribers: mathieubaudet

Differential Revision: https://phabricator.fb.com/D1558290

Tasks: 5134636
[clang 3.6dev] More updates to follow clang's ASTDumper

Summary: [clang 3.6dev] More updates to follow clang's ASTDumper

Test Plan: make test && make -C clang-ocaml test

Reviewers: ddino, dulmarod, irp

Reviewed By: irp

Subscribers: mathieubaudet

Differential Revision: https://phabricator.fb.com/D1558295

Tasks: 5134636