WASIX: Architecture-Independent StackSnapshot Alignment

[theduke]

The StackSnapshot type used by wasix is currently defined as a u128, which creates alignment issues on different CPU architectures, for example because ARM has different alignment requirements.

The type should be replaced to be free of alignment issues, like a multiple u32.

This may also require updates to:

• WASIX Rust bindings
  https://github.com/john-sharratt/wasix
  (This currently has the type defined with two u64 fields...
• WASIX libc
  https://github.com/wasmerio/wasix-libc

[ptitSeb]

assigned to syrus for later assignment.

[ptitSeb]

Main type aligment done. Need some 2nd look on that later.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[syrusakbary]

Not stale

[stale]

Feel free to reopen the issue if it has been closed by mistake.