Update more rustc/libtest things for wasm64

* Add wasm64 variants for inline assembly along the same lines as wasm32
* Update a few directives in libtest to check for `target_family`
  instead of `target_arch`
* Update some rustc codegen and typechecks specialized for wasm32 to
  also work for wasm64.

Author: alexcrichton

test/src/console.rs

@@ -284,7 +284,7 @@ pub fn run_tests_console(opts: &TestOpts, tests: Vec<TestDescAndFn>) -> io::Resu
     // Prevent the usage of `Instant` in some cases:
     // - It's currently not supported for wasm targets.
     // - We disable it for miri because it's not available when isolation is enabled.
-    let is_instant_supported = !cfg!(target_arch = "wasm32") && !cfg!(miri);
+    let is_instant_supported = !cfg!(target_family = "wasm") && !cfg!(miri);
 
     let start_time = is_instant_supported.then(Instant::now);
     run_tests(opts, tests, |x| on_test_event(&x, &mut st, &mut *out))?;

test/src/lib.rs

@@ -470,7 +470,7 @@ pub fn run_test(
 
     // Emscripten can catch panics but other wasm targets cannot
     let ignore_because_no_process_support = desc.should_panic != ShouldPanic::No
-        && cfg!(target_arch = "wasm32")
+        && cfg!(target_family = "wasm")
         && !cfg!(target_os = "emscripten");
 
     if force_ignore || desc.ignore || ignore_because_no_process_support {
@@ -519,7 +519,7 @@ pub fn run_test(
         // If the platform is single-threaded we're just going to run
         // the test synchronously, regardless of the concurrency
         // level.
-        let supports_threads = !cfg!(target_os = "emscripten") && !cfg!(target_arch = "wasm32");
+        let supports_threads = !cfg!(target_os = "emscripten") && !cfg!(target_family = "wasm");
         if concurrency == Concurrent::Yes && supports_threads {
             let cfg = thread::Builder::new().name(name.as_slice().to_owned());
             let mut runtest = Arc::new(Mutex::new(Some(runtest)));