Use capstone to validate precise-output tests (#5780)

Use the capstone library to disassemble precise-output tests, in addition to pretty-printing their vcode.

cranelift/filetests/src/test_wasm.rs

@@ -61,7 +61,7 @@ pub fn run(path: &Path, wat: &str) -> Result<()> {
                 .compile(isa)
                 .map_err(|e| crate::pretty_anyhow_error(&e.func, e.inner))?;
             writeln!(&mut actual, "function {}:", func.name).unwrap();
-            writeln!(&mut actual, "{}", code.disasm.as_ref().unwrap()).unwrap();
+            writeln!(&mut actual, "{}", code.vcode.as_ref().unwrap()).unwrap();
         } else if config.optimize {
             let mut ctx = cranelift_codegen::Context::for_function(func.clone());
             ctx.optimize(isa)