fix the atomic operation when address misalignment

deps/oblib/src/lib/thread/threads.h

@@ -140,7 +140,7 @@ private:
   int64_t stack_size_;
   bool stop_;
   // protect for thread count changing.
-  common::SpinRWLock lock_;
+  common::SpinRWLock lock_ __attribute__((__aligned__(16)));
   // tenant ctx
   IRunWrapper *run_wrapper_;
   // thread cgroups

src/observer/ob_server.h

@@ -317,7 +317,7 @@ public:
   volatile bool need_ctas_cleanup_; //true: ObCTASCleanUpTask should traverse all table schemas to find the one need be dropped
 private:
   //thread to deal signals
-  char sig_buf_[sizeof(ObSignalWorker) + sizeof(ObSignalHandle)];
+  char sig_buf_[sizeof(ObSignalWorker) + sizeof(ObSignalHandle)] __attribute__((__aligned__(16)));
   ObSignalWorker *sig_worker_;
   ObSignalHandle *signal_handle_;