Pre-RFC: Remove Rust's dependency on Visual Studio in 4 (...complex?) steps

[bjorn3]

@simonbuchan

Do you mean existing C++ libraries built against vcruntime would not have the personality function they expect available at link? Or that C++ code built as part of a crate would need to use the same personality?

Both

@simonbuchan

Either way, throwing across FFI is still UB

extern "C-unwind" may be stabilized in the near future. Throwing across extern "C-unwind" is fully allowed and in fact the reason this ABI has been introduced.