Torque semantic analysis is now a four-stage process:

 1. The TypeDeclarationVisitor introduces a TypeAlias for every
    TypeDeclaration* (or derived) in the Torque source, but does
    not process the TypeDeclaration* itself.
 2. All aliases are resolved in a dependency respecting manner.
    This CL also changes struct member resolution to happen at
    this point already. Types for classes are created, but their
    members are not resolved to allow classes to mutually reference
    each other in their field types.
 3. 'value' declarations (macros, etc.) are processed.
 4. Members of classes are processed.

Bug: v8:7793
Change-Id: I46108555a5cdf30df03c5d4399ec786ee6cc6df4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1584319
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61264}