Instructions for compiling in a readme

[Jacoby6000]

Project won't build on a stable version of rust.

error[E0554]: #![feature] may not be used on the stable release channel
 --> /Users/jacobbarber/.cargo/registry/src/github.com-1ecc6299db9ec823/spin-0.4.6/src/lib.rs:6:30
  |
6 | #![cfg_attr(feature = "asm", feature(asm))]
  |                              ^^^^^^^^^^^^^

error[E0554]: #![feature] may not be used on the stable release channel
 --> /Users/jacobbarber/.cargo/registry/src/github.com-1ecc6299db9ec823/spin-0.4.6/src/lib.rs:7:42
  |
7 | #![cfg_attr(feature = "core_intrinsics", feature(core_intrinsics))]
  |                                          ^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0554]: #![feature] may not be used on the stable release channel
 --> /Users/jacobbarber/.cargo/registry/src/github.com-1ecc6299db9ec823/spin-0.4.6/src/lib.rs:8:35
  |
8 | #![cfg_attr(feature = "const_fn", feature(const_fn, const_unsafe_cell_new, const_atomic_usize_new))]
  |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 3 previous errors

Might be helpful to include information about what nightly build/rust version you're using. People who are new to rust will struggle to get past this.

[roblabla]

Yup. People need to install the very latest nightly right now, as I'm using some very very bleeding edge stuff, such as the lld support that was merged literally 2 days ago. Also, the codebase is kinda messy right now, as I'm iterating on different ideas. It doesn't yet support IPC buffers, which heavily restricts what IPC functions you can call.

When the dust settles a bit, I'll start documenting stuff properly.

[FenrirWolf]

I only just got everything compiling a bit ago. I needed the latest Rust nightly (2018/03/07), needed to submit a fix to Xargo that's now released as v3.11, and I also needed aarch64-none-elf-gcc from devkitA64 to make the cc crate happy (I feel like that last part shouldn't be necessary but I couldn't find a way around it).

So yeah, it's a bit tricky at the moment =P

[roblabla]

Ah yeah, see #10 for the cc crate thing

[FenrirWolf]

Should this be marked as solved now?