[Driver] Refactor to use llvm Option's new Visibility flags

This is a big refactor of the clang driver's option handling to use
the Visibility flags introduced in https://reviews.llvm.org/D157149.
There are a few distinct parts, but they can't really be split into
separate commits and still be made to compile.

1. We split out some of the flags in ClangFlags to ClangVisibility.
   Note that this does not include any subtractive flags.

2. We update the Flag definitions and OptIn/OptOut constructs in
   Options.td by hand.

3. We introduce and use a script, update_options_td_flags, to ease
   migration of flag definitions in Options.td, and we run that on
   Options.td. I intend to remove this later, but I'm committing it so
   that downstream forks can use the script to simplify merging.

4. We update calls to OptTable in the clang driver, cc1as, flang, and
   clangd to use the visibility APIs instead of Include/Exclude flags.

5. We deprecate the Include/Exclude APIs and add a release note.

*if you are ...