Generating C++ source files is very cumbersome using raw ostreams. This
CL introduces a few classes und the torque::cpp namespace that build an
abstraction of printing/formatting C++ source code (mostly functions for
now).

This is an initial implementation with a limited set of features and
uses. Landing features incrementally shall avoid huge CLs (+reviews) and
complex rebasing.

Bug: v8:7793
Change-Id: I3ae869755156175c7b37ea9f649e2f9c431ce3a3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2784688Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Seth Brenith <seth.brenith@microsoft.com>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74705}