[Parser] Parse br_on_cast{_fail} input annotations

[tlively]

And validate in IRBuilder both that the input annotation is valid and that the
input matches it.

[tlively]

Current dependencies on/for this PR:

• main
  • PR [Parser] Parse folded instructions that contain parentheses #6196
    • PR Drop support for type annotations on array.len #6197
      • PR [Parser] Parse br_on_cast{_fail} input annotations #6198 👈
        • PR [Parser] Go back to "sub final" intead of "sub open" #6199
          • PR Use the standard shared memory text format #6200

This stack of pull requests is managed by Graphite.

[tlively]

Merge activity

• Jan 3, 4:37 PM: Graphite rebased this pull request as part of a merge.
• Jan 3, 5:04 PM: @tlively merged this pull request with Graphite.