add CI tests of MIRI

.github/workflows/miri.yml

@@ -0,0 +1,18 @@
+on:
+  pull_request:
+
+test_miri:
+  name: Test (Miri)
+  runs-on: ubuntu-latest
+  steps:
+    - uses: actions/checkout@v2
+    - uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: nightly
+        override: true
+        components: miri
+    - uses: actions-rs/cargo@v1
+      with:
+        command: miri
+        args: test miri

src/sys/tskbox.rs

@@ -42,7 +42,7 @@ fn is_send_sync<T: Send + Sync>(t: &T) {}
 // work accross FFI.
 
 #[test]
-fn test() {
+fn test_miri() {
     struct X {
         data: i32,
     }