Document Wasm exception handling

[chrisdavidmills]

Description

This PR adds documentation for "modern" WebAssembly Exception handling. I am not intending to document "legacy" Wasm exception handling alongside this, as it would make the documentation significantly more complex (some features are used in both), and I'm sure we want to encourage devs to use the modern version.

Specifically, this PR documents the following:

• tag definition
• exnref type
• throw instruction
• throw_ref instruction
• try_table instruction
• catch instruction
• catch_all instruction
• catch_ref instruction
• catch_ref_all instruction

I am also going to check whether the following, already existing, ref docs need any updates:

• WebAssembly.Tag and members
• WebAssembly.Exception and members

Motivation

Additional details

Related issues and pull requests

[github-actions]

Preview URLs (1 page)

• /en-US/docs/WebAssembly/Reference/Definitions/tag

Flaws (12)

Found an unexpected or unresolvable flaw? Please report it here.

URL: /en-US/docs/WebAssembly/Reference/Definitions/tag
Title: tag: Wasm definition
Flaw count: 12

• broken_links:
  • Link /en-US/docs/WebAssembly/Reference/Types/exnref doesn't resolve
  • Link /en-US/docs/WebAssembly/Reference/Exception_handling/try_table doesn't resolve
  • Link /en-US/docs/WebAssembly/Reference/Exception_handling/catch doesn't resolve
  • Link /en-US/docs/WebAssembly/Reference/Exception_handling/catch_all doesn't resolve
  • Link /en-US/docs/WebAssembly/Reference/Exception_handling/catch_ref doesn't resolve
  • and 7 more flaws omitted