Rollup merge of #131654 - betrusted-io:xous-various-fixes, r=thomcc

Various fixes for Xous

This patchset includes several fixes for Xous that have crept in over the last few months:

* The `adjust_process()` syscall was incorrect
* Warnings have started appearing in `alloc` -- adopt the same approach as wasm, until wasm figures out a workaround
* Dead code warnings have appeared in the networking code. Add `allow(dead_code)` as these structs are used as IPC values
* Add support for `args` and `env`, which have been useful for running tests
* Update `unwinding` to `0.2.3` which fixes the recent regression due to changes in `asm!()` code

Author: matthiaskrgr