Add a compile command to Wasmtime.

This commit adds a `compile` command to the Wasmtime CLI.

The command can be used to Ahead-Of-Time (AOT) compile WebAssembly modules.

With the `all-arch` feature enabled, AOT compilation can be performed for
non-native architectures (i.e. cross-compilation).

The `Module::compile` method has been added to perform AOT compilation.

A few of the CLI flags relating to "on by default" Wasm features have been
changed to be "--disable-XYZ" flags.

A simple example of using the `wasmtime compile` command:

```text
$ wasmtime compile input.wasm
$ wasmtime input.cwasm
```

crates/jit/src/compiler.rs

@@ -5,6 +5,7 @@ use crate::object::{build_object, ObjectUnwindInfo};
 use object::write::Object;
 #[cfg(feature = "parallel-compilation")]
 use rayon::prelude::*;
+use serde::{Deserialize, Serialize};
 use std::hash::{Hash, Hasher};
 use std::mem;
 use wasmparser::WasmFeatures;
@@ -18,7 +19,7 @@ use wasmtime_environ::{
 };
 
 /// Select which kind of compilation to use.
-#[derive(Copy, Clone, Debug, Hash)]
+#[derive(Copy, Clone, Debug, Hash, Serialize, Deserialize, Eq, PartialEq)]
 pub enum CompilationStrategy {
     /// Let Wasmtime pick the strategy.
     Auto,
@@ -108,6 +109,11 @@ impl Compiler {
         self.isa.as_ref()
     }
 
+    /// Return the compiler's strategy.
+    pub fn strategy(&self) -> CompilationStrategy {
+        self.strategy
+    }
+
     /// Return the target's frontend configuration settings.
     pub fn frontend_config(&self) -> TargetFrontendConfig {
         self.isa.frontend_config()