IDL compiler: Types

This is a basic CL for the compiler, doing various type handling and
conversion.
It's rather long (600 lines), but primarily data tables, and the logic
is very flat.

BUG=239771

Review URL: https://chromiumcodereview.appspot.com/24257003

git-svn-id: svn://svn.chromium.org/blink/trunk@158239 bbb929c8-8fbe-4397-9dbb-9b2b20218538