Tracked upstream issues

[purplesyringa]

Important stuff:

• ScopeGuard/MutexGuard/etc. act weirdly due to Panic backend has incompatible std::panic::panicking behavior #6, track Nested panics and std::thread::panicking rust-lang/rust#143612 and Is mutex poisoning guaranteed to always work properly? rust-lang/rust#143471

Wine issues:

• i686 Wine is broken
• TLS alignment is broken on Wine

Potential undefined behavior:

• Call for formalization of _Unwind_Resume preconditions
• Inconsistency in Itanium EH ABI on catching foreign exceptions

Bugs not usually triggered bv user code:

• LLVM miscompiles unwinding over foreign ABIs

Issues with non-tier 1 targets:

• How Emscripten JS/Wasm EH needs to be detected is uncertain
• Wine does not support arm64ec out of the box yet, needs recompile from source

Non-critical miscellaneous tasks:

• Call for a standard Rust mechanism for catching foreign panics
• Configuring required panic strategy
• iex chore

Resolved problems:

• MIPS target was broken: rustc side, LLVM side
• arm64ec was broken in rust
• WASM trying and throwing were broken