This change adds Torque field definitions for ScopeInfo and begins to
use the Torque-generated accessors in some places. It does not change
the in-memory layout of ScopeInfo.

Torque compiler changes:

- Fix an issue where the parser created constexpr types for classes
  based on the class name rather than the `generates` clause. This meant
  that generated accessors referred to the imaginary type HashTable
  rather than the real C++ type FixedArray.
- Don't pass Isolate* through the generated runtime functions that
  implement Torque macros. Maybe we'll need it eventually, but we don't
  right now and it complicates a lot of things.
- Don't emit `kSomeFieldOffset` if some_field has an unknown offset.
  Instead, emit a member function `SomeFieldOffset()` which fetches the
  slice for some_field and returns its offset.
- Emit an `AllocatedSize()` member function for classes which have
  complex length expressions. It fetches the slice for the last field
  and performs the multiply&add to compute the total object size.
- Emit field accessors for fields with complex length expressions, using
  the new offset functions.
- Fix a few minor bugs where Torque can write uncompilable code.

With this change, most code still treats ScopeInfo like a FixedArray, so
I would like to follow up with some additional changes:

1. Generate a GC visitor for ScopeInfo and use it
2. Generate accessors for struct-typed fields (indexed or otherwise),
   and use them
3. Get rid of the FixedArray-style get and set accessors; use
   TaggedField::load and similar instead
4. Inherit from HeapObject rather than FixedArrayBase to remove the
   unnecessary `length` field

After that, there will only be one ugly part left: initialization. I
think it's possible to generate a factory function that takes a bunch of
iterator parameters and returns a fully-formed, verifiably correct
ScopeInfo instance, but doing so is more complicated than the four
mostly-mechanical changes listed above.

Bug: v8:7793
Change-Id: I55fcfe9189e4d1613c68d49e378da5dc02597b36
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2357758Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#72187}