Call into fastfail on abort in libpanic_abort on Windows x86(_64)

[rylev]

This partially resolves #73215 though this is only for x86 targets. This code is directly lifted from libstd. __fastfail is the preferred way to abort a process on Windows as it will hook into debugger toolchains.

Other platforms expose a _rust_abort symbol which wraps std::sys::abort_internal. This would also work on Windows, but is a slightly largely change as we'd need to make sure that the symbol is properly exposed to the linker. I'm inlining the call to the __fastfail, but the indirection through rust_abort might be a cleaner approach.

A different instruction must be used on ARM architectures. I'd like to verify this works first before tackling ARM.

[rust-highfive]

r? @shepmaster

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[mati865]

Is there a reason to duplicate the code instead of calling already existing function?

[rylev]

The function is not available as it's defined in standard and panic_abort is !#[no_std]. The trick pulled by some targets is to expose a __rust_panic symbol which is linked to when linking panic_abort and the standard library. We can also use that trick here I believe. I'm just not familiar enough with the mechanics of how std gets built to ensure that it works properly.

[alexcrichton]

The already existing function only exists in libstd I believe which panic_abort can't depend on. I'm not sure what's up with __rust_abort but that looks like it's for niche use cases, and the amount of duplication here is just one line, so I think duplication is fine here.

[shepmaster]

@alexcrichton would you feel comfortable taking this review? I definitely don't understand it enough.

[alexcrichton]

Sure!

@bors: r+

[bors]

📌 Commit b9b8b5c has been approved by alexcrichton

[bors]

⌛ Testing commit b9b8b5c with merge 3d6a3ed...

[bors]

☀️ Test successful - checks-actions, checks-azure
Approved by: alexcrichton
Pushing 3d6a3ed to master...