10769: Add proc macro ABI for rustc 1.58 r=lnicola a=alexjg
This fixes#10766.
I do have some concerns here. The proc macro server API has added three methods to `TokenStream` which I don't really know how to implement in `RustcServer`. Namely `expand_expr`, `before`, and `after`. You'll see that these are currently `unimplemented!` in `crates/proc_macro_server/src/abis/abi_1_58/rustc_server.rs`. I don't have the expertise to fill in the blanks here, it may be necessary to pull in someone who knows a bit more about the proc macro crate.
I think this will only be a problem when actually attempting to expand a macro, so this is probably strictly better than not including the updated ABI at all.
Co-authored-by: Alex Good <alex@memoryandthought.me>
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