Move /src/test to /tests

tests/ui/process/process-spawn-nonexistent.rs

@@ -0,0 +1,17 @@
+// run-pass
+// ignore-emscripten no processes
+// ignore-sgx no processes
+// ignore-fuchsia ErrorKind not translated
+
+use std::io::ErrorKind;
+use std::process::Command;
+
+fn main() {
+    let result = Command::new("nonexistent").spawn().unwrap_err().kind();
+
+    assert!(matches!(
+        result,
+        // Under WSL with appendWindowsPath=true, this fails with PermissionDenied
+        ErrorKind::NotFound | ErrorKind::PermissionDenied
+    ));
+}