Add support for the experimental wasi-crypto APIs (#2597)

* Add support for the experimental wasi-crypto APIs

The sole purpose of the implementation is to allow bindings and
application developers to test the proposed APIs.

Rust and AssemblyScript bindings are also available as examples.

Like `wasi-nn`, it is currently disabled by default, and requires
the `wasi-crypto` feature flag to be compiled in.

* Rename the wasi-crypto/spec submodule

* Add a path dependency into the submodule for wasi-crypto

* Tell the publish script to vendor wasi-crypto

scripts/publish.rs

@@ -65,6 +65,7 @@ const CRATES_TO_PUBLISH: &[&str] = &[
     "wasmtime-wiggle",
     "wasmtime-wasi",
     "wasmtime-wasi-nn",
+    "wasmtime-wasi-crypto",
     "wasmtime-rust-macro",
     "wasmtime-rust",
     "wasmtime-wast",
@@ -176,7 +177,7 @@ fn read_crate(manifest: &Path) -> Crate {
     } else {
         version.clone()
     };
-    if name == "witx" {
+    if ["witx", "wasi-crypto"].contains(&&name[..]) {
         publish = false;
     }
     Crate {
@@ -299,6 +300,13 @@ fn verify(crates: &[Crate]) {
         .unwrap();
     verify_and_vendor(&witx);
 
+    // Vendor wasi-crypto which is also a path dependency
+    let wasi_crypto = crates
+        .iter()
+        .find(|c| c.name == "wasi-crypto")
+        .unwrap();
+    verify_and_vendor(&wasi_crypto);
+
     for krate in crates {
         if !krate.publish {
             continue;