IDL Compiler: Implement IR class for includes, enumeration, typedef

This CL defines a basic structure of IR class for includes, enumeration,
and typedef. Also converts ASTs into these classes.


Bug: 839389
Change-Id: I0193189f151f6ff0f74e7d1f08a5d4e285981473
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1647263
Commit-Queue: Hitoshi Yoshida <peria@chromium.org>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#675157}
5 files changed