Add standalone cases (#3536)

tests/standalone/test-pthread/thread_exit.c

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2023 Intel Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include <pthread.h>
+#include <stdio.h>
+
+/* Start function for the background thread */
+void *
+bg_func(void *arg)
+{
+    printf("Thread start.\n");
+    while (1) {
+        pthread_exit(NULL);
+    }
+}
+
+/* Foreground thread and main entry point */
+int
+main(int argc, char *argv[])
+{
+    pthread_t bg_thread;
+
+    if (pthread_create(&bg_thread, NULL, bg_func, NULL)) {
+        printf("Thread create failed");
+        return 1;
+    }
+    printf("Thread created.\n");
+
+    /* Wait for background thread to finish */
+    if (pthread_join(bg_thread, NULL)) {
+        printf("Thread join failed");
+        return 2;
+    }
+
+    printf("Sub-thread exit.\n");
+    printf("Test success.\n");
+
+    return 0;
+}