Implement TLS and spinlocks, fix bug in Windows threads

src/thread_null.c

@@ -367,6 +367,45 @@ int bh_thread_pool_init(bh_thread_pool_t *pool,
     return BH_NO_IMPL;
 }
 
+void bh_spinlock_init(bh_spinlock_t *lock)
+{
+    lock->handle = 0;
+}
+
+void bh_spinlock_destroy(bh_spinlock_t *lock)
+{
+    (void)lock;
+}
+
+int bh_spinlock_lock(bh_spinlock_t *lock)
+{
+    return BH_NO_IMPL;
+}
+
+int bh_spinlock_unlock(bh_spinlock_t *lock)
+{
+    return BH_NO_IMPL;
+}
+
+int bh_spinlock_try_lock(bh_spinlock_t *lock)
+{
+    return BH_NO_IMPL;
+}
+
+bh_tls_info_t *bh_tls_info(void)
+{
+    static bh_tls_info_t info;
+
+    return &info;
+}
+
+bh_tls_t *bh_tls_fetch(void)
+{
+    static bh_tls_t tls;
+
+    return &tls;
+}
+
 /**
  * \}
  */