Auto merge of #85557 - hyd-dev:abi, r=RalfJung

Add `rustc_mir::interpret::Machine::enforce_abi()`

To specify whether to skip the [ABI](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_target/abi/enum.Abi.html) check for function calls, so that we could test unwinding out of a `extern "C"` function call in Miri by disabling the check: https://github.com/rust-lang/miri/pull/1776#discussion_r633698382

I have tested that it works in Miri with a `-Zmiri-disable-abi-check` command line flag.