Effects refactor

Bugfix

Run finalizers on large alloc blocks

Refactor all .sexp targets into flags.sexp.

ac520fe Merge flambda-backend changes
45cbc7d Turn "include functor" extension on by default (ocaml#38)
1531a02 Add the "include_functor" extension. (ocaml#32)
67b25c1 Merge flambda-backend changes

git-subtree-dir: ocaml
git-subtree-split: ac520fe

This extension adds the structure item form "include functor F", where F must be
a functor whose parameter can be "filled in" with the previous contents of the
current module.  This eliminates a common source of boilerplate where modules
create submodules that duplicate some of their contents and exist only for the
purpose of applying a functor.  For example:

    module Foo = struct
      module T = struct
        type t = int [@@deriving compare]
      end

      include T
      include Comparable.Make(T)
    end

Can now be written:

    module Foo = struct
      type t = int [@@deriving compare]

      include functor Comparable.Make
    end

Where the only difference is that the latter Foo doesn't have the submodule T.

* convert "support" page to use markdown; add next-mdx-remote bindings, simplify markdown and mdx modules
* Also: remove vercel config to reduce number of configs