In the process turn the Torque's Arguments type into a real struct
and add interoperability with it and CSA's CodeStubArguments.

This change is motivated by the desire to include Arguments
in structs (e.g. iterators), which is not possible for constexpr
fields.

Bug: v8:7793
Change-Id: I840538b84c4c58fee75e0b9cd3bdbb3b96a6b948
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1549162
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60597}