I'm trying to remove annotations and make behavior more consistent. For
@generatePrint, there are two options: either generate printers for
every extern class, or never generate printers for extern classes. This
change implements the option of always generating printers. Classes that
require custom printing can easily hide the generated printer by using
DECL_PRINTER. This causes the generated file
gen/torque-generated/objects-printer.cc to grow to 1600 lines, including
many functions that are never used, but I think the consistency benefit
outweighs a little more compilation time on one file. This change also
removes custom printers in cases where the generated printer includes
all of the same content.

If folks would prefer the option to never generate printers, I'm open to
doing that instead. I like the notion that generating more code could
reduce the friction of adding new classes and thereby encourage people
to define precise types rather than using FixedArrays, but the current
implementation of generated printers is limited, and many printers have
been customized to show the data that matters the most. Unlike verifiers
and body descriptors, there are no correctness or safety concerns with
hand-written printers.

Some bugs showed up once we start generating printers for everything,
and this change fixes them:
- Printers incorrectly included ungettable fields like padding
- Printers called getters which might be hidden by hand-written classes
- The generated getter for Map::instance_type used
  ReadField<InstanceType>, which is not an arithmetic type since it's an
  enum

One more tiny drive-by fix: added a missing newline in the printers for
JSMap and JSSet.

Bug: v8:7793
Change-Id: Ib9e9575fbcb57879935ff18bf4db49fe276d2966
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3172190Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#77152}