Fix ICE emitted when unsized parameters are passed to functions with x86-interrupt ABI.

[Siech0]

This PR aims to solve an issue where unsized types could be passed to the x86-interrupt ABI and cause an ICE to be emitted.

Note: There was an update to the note message used when the extern "tail" abi encounters an error with the same root cause. These behaviors felt correlated enough that adding a note here would be useful to the end users of both. If this is undesirable, reverting this behavior is trivial.

Relevant unstable feature: #40180
Fixes #124806

---

LLM Policy disclaimer: An LLM agent was used in the analysis of the codebase and the self-review of this PR. Specifically, with prompts in the form of:

• What region of code is relevant to these behaviors? What types, functions, etc, are relevant here?
• Which files do I need to review before proceeding?

The addition to suggestions.rs (in the oh-so-helpful way they like to when not asked to) was LLM proposed and human verified. The code was trivial enough that alternatives didn't seem reasonable.

[rustbot]

Thanks for the pull request, and welcome! The Rust Project has assigned @khyperia (or someone else) to review your changes, you should hear from them (or someone else) within the next two weeks.

Please see the contribution instructions and our LLM policy for more information.

Why was this reviewer chosen?

The reviewer was selected based on:

• Owners of files modified in this PR: compiler
• compiler expanded to 75 candidates
• Random selection from 19 candidates

[Siech0]

I did more thinking about this problem and decided to go about it in a different manner after applying more research. I have opened another PR (#162457), which I believe subsumes this one and handles it more correctly.