Web Assembly target support

[rjzak]

Get steward to compile for Web Assembly. Currently, these modules are blocking this:

• Socket2: axum->hyper->socket2, axum->hyper->h2->tokio->socket2

[rjzak]

Internal PR:

• feat: Intel assembly behind x86_64 arch sgx#93
• wasi-crypto support enarx#2116

External PRs:

• Wasm32-wasi target support tokio-rs/mio#1576
• fix(wasi): don't fail select() on empty subscriptions tokio-rs/mio#1580
• fix: don't try_clone() a debug-only field tokio-rs/mio#1581
• Wasm32-wasi target support tokio-rs/tokio#4716
• feat: wasm32-wasi target support hyperium/hyper#2900
• feat: ECDSA_P384_SHA384 support WebAssembly/wasi-crypto#61
• Include p384 in the set of required curves for signatures and ECDH WebAssembly/wasi-crypto#62 (non-Profian person)
• Update Dependencies dalek-cryptography/curve25519-dalek#403
  • curve25519-dalek unmaintained WebAssembly/wasi-crypto#63
• feat: support ECDSA_P384_SHA384 WebAssembly/wasi-crypto#64
• Boring and rustcrypto rsa WebAssembly/wasi-crypto#71
• Update wasi-crypto bytecodealliance/wasmtime#4612
• feat: add sha-384 hashing WebAssembly/wasi-crypto#80

Test applications:

• rjzak/tokio-echo-test for Tokio on Wasi
• rjzak/axum-wasm-test for Axum & Tokio on Wasi
• rjzak/wasi-crypto-example for Wasi-crypto example

Seems a new release of Mio is needed, then the Tokio PR can be updated to use that new Mio release.

[rjzak]

Closed via #63