AWS Nitro Enclaves

[MoSalemIb]

We need to target not only Intel SGX but also AWS Nitro Enclaves. We already had a minimal version of this that is capable of running node-agent. Recently I’ve picked this up and am trying to get a proper toolchain that can pass its own tests.

Todo:

Port existing branch of the Rust compiler to a more recent version

API-review: Agree on the enclave/runner interface

Review of various tools

Make sure Rust compiler tests pass

Upstream the entire thing

Make sure enclave runner services can be shared between SGX and Nitro Enclaves

Setting up CI