The feature gate for the issue is #![feature(asm_unwind)].

Summary

This feature adds a may_unwind option to asm! which allows an asm block to unwind stack and be part of the stack unwinding process. This option is only supported by the LLVM backend right now.

Status

Blocked on the stabilization of extern "C-unwind" (#74990).

Also it is uncertain whether this can be supported directly by non-LLVM backends. It is possible to support by outlining the assembly code to a separate function and calling it.