This change generates functions that verify the things that Torque knows
about objects and their fields. We still must implement each verifier
function in objects-debug.cc, but we can call into the generated code to
verify that field types match their Torque definitions. If no additional
verification is required, we can use the macro USE_TORQUE_VERIFIER as a
shorthand for a verifier that calls the corresponding generated
function.

A new annotation @noVerifier can be applied to both class and field
definitions, to prevent generating verification code. This allows fully
customized verification for complicated cases like
JSFunction::prototype_or_initial_map, which might not exist at all, and
JSObject::elements, which might be a one pointer filler map.

Because Factory::InitializeJSObjectFromMap fills new objects with
undefined values, and many verifiers need to deal with partially-
initialized objects, the generated verifiers allow undefined values on
every class deriving from JSObject. In cases where stricter checks were
previously performed, they are kept in objects-debug.cc.

Bug: v8:7793
Change-Id: I84034efadca89ba0aceddf92e886ffbfaa4c23fa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1594042
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61422}